Our Network


Coming Soon


Coming Later

Calendar Date Rounder

World's Simplest Time Tool

With this browser-based application, you can round a calendar date up, down, or to the next nearest date. You can adjust the rounding precision in the options and round the date to a day, month, quarter, year, ten years, and century. You can quickly switch between the three rounding methods and instantly get the rounded date in the output. Created by computer nerds from team Browserling.

᠎᠎᠎          Tool Options

Date Rounding Precision

Round a date with this
precision.
Round up to 1 month:
2020-08-12 → 2020-09-01.
Round up to 1 quarter:
2020-08-12 → 2020-10-01.
Round up to 1 year:
2020-08-12 → 2021-01-01.
Round up to 1 century:
2020-08-12 → 2100-01-01.

Date Round Method

Use the ceil method to
round a date up.
Use the floor method to
round a date down.
Automatically determine whether
to use ceil or floor method to
round a date.

Date Rounding Examples

Round days up:
2020-08-12 20:00:00 →
2020-08-13 00:00:00.

Round months down:
2020-08-12 20:00:00 →
2020-08-01 00:00:00.

Round to nearest year:
2020-08-12 20:00:00 →
2021-01-01 00:00:00.

What Is a Calendar Date Rounder?

This is a quick online utility for rounding calendar dates. It can round any date to any precision up, down, or to the closest date. When a date is rounded, the least significant date components are set to the smallest possible value (zero for hours/minutes/seconds and one for years/months/days). For example, if the date "2022-05-21 14:23:58" is rounded down to days, then the hours, minutes, and seconds components turn into zeros "2022-05-21 00:00:00". Similarly, when this same date is rounded down to months, we get "2022-05-01 00:00:00", to quarters: "2022-04-01 00:00:00", to years: "2022-01-01 00:00:00", to decades (tens of years): "2020-01-01 00:00:00", and to centuries: "2000-01-01 00:00:00". You can also round time part of a date to an hour, 30 minutes, 15 minutes, 10 minutes, 5 minutes, 1 minute, 30 seconds, 10 seconds, and 5 seconds. In the options, you can switch between three rounding methods: "Round a Date Up", "Round a Date Down", and "Round Date to Nearest". Rounding up increases the date components towards the next largest day/month/year/century. For example, the date "2022-05-21 14:23:58" will become "2022-06-01 00:00:00" when rounding the months up. Rounding down decreases the date components to the beginning of the smallest day/month/year/century. For example, when rounding the date "2022-05-21 14:23:58" down to months, we get "2022-05-01 00:00:00". Rounding to the nearest date determines on its own whether to increase or decrease the date. For example, when rounding the date "2022-05-21 14:23:58" to the nearest day, it becomes "2022-06-01 00:00:00" (because it's 10 days from June and 21 from May), and the date "2022-05-03 14:23:58" becomes "2022-05-01 00:00:00" (because it's 3 days from May and 28 days from June). You can round as many dates as you want at the same time if you enter them one per line to the input. The rounding results can be copied or saved from the output field. Timeabulous!


Calendar Date Rounder Examples

Click to try!

Round a Date to a Day

In this example, we round up three calendar dates with a precision of one day. Every date that has a clock time part greater than midnight turns into the start of the next day. If the clock time is exactly midnight, then the time is already rounded to a day and doesn't change.

2000-11-24 05:20:50 2034-05-31 16:00:00 2050-02-12 00:00:00
2000-11-25 00:00:00 2034-06-01 00:00:00 2050-02-12 00:00:00
Required options
These options will be used automatically if you select this example.
Round a date with this
precision.
Use the ceil method to
round a date up.

Round Months Down

This example sets each date to the beginning of the month. Here the rounding algorithm uses the "Round a Date Down" mode with a precision of 1 month. As a result, all calendar days are set to "01" and the time is reset to 00:00:00.

1995-11-23 17:30:00 1980-06-01 00:00:00
1995-11-01 00:00:00 1980-06-01 00:00:00
Required options
These options will be used automatically if you select this example.
Round a date with this
precision.
Use the floor method to
round a date down.

Find the Middle of the Year

In this example, we use our date rounding program to guess the middle of a leap year and a common year. We set the options to round the given dates to the closest year and enter several leap years (2024) and several common years (2025) in the input that have a difference of 1 second. We can see that the middle of a leap year falls on the midnight of July 2nd (on 2024-07-02 00:00:00) and the middle of a regular year falls on the noon of July 2nd (2025-07-02 12:00:00).

2024-07-01 23:59:59 2024-07-02 00:00:00 2025-07-02 11:59:59 2025-07-02 12:00:00
2024-01-01 00:00:00 2025-01-01 00:00:00 2025-01-01 00:00:00 2026-01-01 00:00:00
Required options
These options will be used automatically if you select this example.
Round a date with this
precision.
Automatically determine whether
to use ceil or floor method to
round a date.

Round Dates in a Quarterly Financial Report

In this example, we are working with a quarterly financial report for q2, 2022. As all dates fit in the interval 2022-04-01 to 2022-07-01, we round them down to the q2 start date. This way all output dates start on the first day on q2, 2022, which is "2022-04-01".

2022-04-28 12:30:00 2022-05-01 06:45:30 2022-05-14 13:05:00 2022-05-31 00:00:00 2022-06-03 04:00:00 2022-06-26 15:00:50
2022-04-01 00:00:00 2022-04-01 00:00:00 2022-04-01 00:00:00 2022-04-01 00:00:00 2022-04-01 00:00:00 2022-04-01 00:00:00
Required options
These options will be used automatically if you select this example.
Round a date with this
precision.
Use the floor method to
round a date down.

Round a Date to 10 Years

In this example, we round up three different dates to the next decade. After rounding, the months and days are set to the beginning of the year (January 1) and the time is reset to midnight. The year is turned into the next largest year divisible by ten. As a result, the first year is rounded to 2030, the second to 2040, and the third to 2050.

2022-06-25 00:00:00 2038-10-10 10:10:10 2044-01-12 09:00:00
2030-01-01 00:00:00 2040-01-01 00:00:00 2050-01-01 00:00:00
Required options
These options will be used automatically if you select this example.
Round a date with this
precision.
Use the ceil method to
round a date up.

Which Century Is a Date Closest To?

In this example, we load a list of random dates from 2000 to 2100 and we want to determine which century each date is closest to. To find the answer, we select the century round precision and switch to the nearest rounding mode. As soon as we do that, we get the answer to our question and all dates are shifted back either to 2000 (if they are closer to 2000) or shifted forward to 2100 (if they are closer to 2100).

2002-03-27 00:53:57 2090-09-27 21:47:19 2005-10-10 01:17:37 2030-07-22 13:10:02 2095-12-12 16:59:45 2089-10-28 13:04:01 2058-03-13 13:13:48 2022-07-21 06:12:01 2057-12-13 00:56:07 2004-04-28 06:36:49
2000-01-01 00:00:00 2100-01-01 00:00:00 2000-01-01 00:00:00 2000-01-01 00:00:00 2100-01-01 00:00:00 2100-01-01 00:00:00 2100-01-01 00:00:00 2000-01-01 00:00:00 2100-01-01 00:00:00 2000-01-01 00:00:00
Required options
These options will be used automatically if you select this example.
Round a date with this
precision.
Automatically determine whether
to use ceil or floor method to
round a date.

Pro tips Master online time tools

You can pass input to this tool via ?input query argument and it will automatically compute output. Here's how to type it in your browser's address bar. Click to try!

https://onlinetools.com/time/round-calendar-date?input=2000-11-24%2005%3A20%3A50%0A2034-05-31%2016%3A00%3A00%0A2050-02-12%2000%3A00%3A00&round-to=to-1-day&round-up=true

All Time Tools

Didn't find the tool you were looking for? Let us know what tool we are missing and we'll build it!
Quickly visualize your life in weeks or months.
Quickly draw a wall clock that shows a particular time.
Quickly draw an electronic clock that shows a particular time.
Quickly draw a monthly calendar for any month of the year.
Quickly print a list of neat-looking clock times (such as 10:11:12).
Quickly print a list of neat-looking calendar dates (such as 2055-05-05).
Quickly print a list of symmetric clock times (such as 05:22:50).
Quickly print a list of symmetric dates (such as 2020-02-02).
Quickly convert clock time in H:M:S format to seconds.
Quickly convert seconds to clock time in H:M:S format.
Quickly convert time in 24 hour format to 12 hour format.
Quickly convert time in 12 hour format to 24 hour format.
Quickly find how many seconds have passed since midnight.
Quickly find how many seconds are left till midnight.
Quickly find the difference between two clock times.
Quickly find the difference between two calendar dates.
Quickly find the age difference between two or more people.
Quickly add hours, minutes, and seconds to the given time.
Quickly subtract hours, minutes, and seconds from the given time.
Quickly add days, months, and years to the given date.
Quickly subtract days, months, and years to from the given date.
Quickly change the current time format to any new format.
Quickly change the current date format to any new format.
Quickly round the given clock time up or down.
Quickly round the given calendar date up or down.
Quickly drop seconds and minutes from a clock time.
Quickly drop days and months from a calendar date.
Quickly sort clock times in ascending or descending order.
Quickly sort calendar dates in ascending or descending order.
Quickly sort time intervals by their start time or length.
Quickly sort date intervals by their start date or length.
Quickly check if the given clock time is valid.
Quickly check if the given calendar date is valid.
Quickly find how many hours are in the given days.
Quickly find how many days are in the given hours.
Quickly find the astrological sign by the birthday or any date.
Quickly print a list of the dates of all astrological signs.
Quickly find the average value of multiple clock times.
Quickly find the average value of multiple calendar dates.
Quickly generate a list of random clock times.
Quickly generate a list of random calendar dates.
Quickly create a list of clock times that match your criteria.
Quickly generate a list of calendar dates that match your criteria.
Quickly split the given time period into multiple intervals.
Quickly split the given date period into multiple intervals.
Quickly generate increasing or decreasing clock times.
Quickly generate increasing or decreasing calendar dates.
Quickly print a list of all leap years.
Quickly print a list of all common years.
Quickly test if the given year is a leap year.
Quickly test if the given year is a common year.
Quickly find how old a cat would be if it was a human.
Quickly find how old a human would be if he/she was a cat.
Quickly find how old a dog would be if it was a human.
Quickly find how old a human would be if it was a dog.
Quickly convert a modern Gregorian date to a Julian date.
Quickly convert an ancient Julian date to a Gregorian date.
Quickly calculate the Julian day number for any calendar date.
Quickly convert the Julian day to a regular calendar date.
Quickly print a list of all Easter dates for all years.
Quickly convert a UNIX Epoch time to a human-readable time.
Quickly convert human-readable time to a UNIX Epoch time.
Quickly generate increasing or decreasing UNIX timestamps.
Quickly generate one or more random UNIX Epoch times.
Quickly convert a HH:MM:SS clock to a military HHMM clock.
Quickly convert a military clock HHMM to a HH:MM:SS clock.
Quickly write a clock time in text format (as English text).
Quickly write a calendar date in text format (as English text).
Quickly add slight perturbations to the given clock times.
Quickly add slight perturbations to the given calendar dates.
Quickly find what day of the week the given calendar date falls on.
Quickly find what day of the year the given calendar date falls on.
Quickly find what week of the year the given calendar date falls on.
Quickly calculate the calendar date from a day number of a year.
Quickly find the angle between the hour hand and minute hand.
Quickly print a list of all clock times with a specific hand angle.
Quickly print all dates when a specific day happens.
Quickly find all Fridays that fall on the 13th day of the month.
Quickly create a list of all Independence Day dates.
Quickly create a list of all Christmas Day dates.
Quickly create a list of all New Year dates.
Quickly create a list of all Thanksgiving dates.
Quickly show useful information about a particular clock time.
Quickly show useful information about a particular calendar date.
Quickly draw a timeline of multiple time intervals.
Quickly draw a visualization of multiple date intervals.
Quickly find the time a clock shows if you look at it in a mirror.
Quickly convert time and date from one timezone to another.
Quickly convert time and date from one country to another.
Quickly print the season (winter, spring, summer, autumn) by date.

Coming Soon

These time tools are on the way!
Draw a Binary Clock

Draw a binary clock that shows time in base two.

Draw a Salvador Dali Clock

Draw a clock in Salvador Dali style showing custom time.

Draw a Weird Clock

Draw a weird-looking clock that shows a particular time.

Draw a Pi Clock

Draw a π clock with π hours in a day.

Draw a 360° Clock

Draw a 360° clock with 360 degrees in a day.

Animate an Analog Clock

Create a GIF animation of an analog clock.

Animate a Digital Clock

Create a GIF animation of a digital clock.

Animate a Broken Clock

Create a GIF animation of a clock that's broken.

Draw a Daily Calendar

Draw a daily calendar for a single day.

Draw a Weekly Calendar

Draw a weekly calendar for any week of the month.

Draw a Yearly Calendar

Draw a yearly calendar for the entire year.

Draw a Lunar Calendar

Draw a calendar that shows moon phases.

Draw a Solar Calendar

Draw a calendar that shows the seasons and Sun's position.

Draw a Sunrise and Sunset Calendar

Draw a calendar that shows when the Sun rises and sets.

Draw a Moonrise and Moonset Calendar

Draw a calendar that shows when the Moon rises and sets.

Create an Animated Timer

Draw an animation that counts down (or up) time.

Animate an Hourglass

Create a GIF animation of a sand clock.

Draw an Infinite Spiral Clock

Animate a timeless clock that goes in an infinite spiral.

Draw Time as a Pie Chart

Visualize the given clock time as a pie chart.

Draw Date as a Pie Chart

Visualize the current year as a pie chart.

Draw Time as a Bar Chart

Visualize the given clock time as a bar chart.

Draw Date as a Bar Chart

Visualize the current year as a bar chart.

Draw Time as a Pixel Wall

Visualize the given clock time as a pixel wall (1px = 1sec).

Draw Date as a Pixel Wall

Visualize the current year as a pixel wall (1px = 1day).

Draw Time as Bubbles

Visualize the given clock time as bubbles.

Draw Date as Bubbles

Visualize the current year as bubbles.

Draw a Time Arrow

Visualize the given clock time as an arrow.

Convert Time to Percentage

Quickly calculate time passed and left in the current day as pct.

Convert Date to Percentage

Quickly calculate time passed and left in the current year as pct.

Convert Time to Binary Time

Convert regular clock time to binary clock time (bintime).

Convert Date to Binary Date

Quickly regular calendar date to binary date (bindate).

Convert Time to Decimal Time

Convert regular clock time to decimal clock time (dectime).

Convert Date to Decimal Date

Quickly regular calendar date to decimal date (decdate).

Convert Time to Hex Time

Convert regular clock time to hexadecimal time (hextime).

Convert Date to Hex Date

Quickly regular calendar date to hexadecimal date (hexdate).

Animate Moon's Phases

Create a GIF animation of the Moon for a particular month.

Animate Moon's Orbit

Create an animation of the Moon orbiting the Earth.

Animate Mercury's Orbit

Create a 88 day animation of the Mercury orbiting the Sun.

Animate Venus's Orbit

Create a 225 day animation of the Venus orbiting the Sun.

Animate Earth's Orbit

Create a 365 day animation of the Earth orbiting the Sun.

Animate Mars's Orbit

Create a 687 day animation of the Mars orbiting the Sun.

Animate Jupiter's Orbit

Create a 4,330 day animation of the Jupiter orbiting the Sun.

Animate Saturn's Orbit

Create a 10,756 day animation of the Saturn orbiting the Sun.

Animate Uranus's Orbit

Create a 30,687 day animation of the Uranus orbiting the Sun.

Animate Neptune's Orbit

Create a 60,190 day animation of the Neptune orbiting the Sun.

Animate Pluto's Orbit

Create a 90,560 day animation of the Pluto orbiting the Sun.

Animate Solar System

Create an animation of all planets in the Solar System.

Animate Mars's Moons

Create an animation of Phobos and Deimos orbiting Mars.

Animate Jupiter's Moons

Animate Io, Europa, Ganymede, Callisto orbiting Jupiter.

Animate Saturn's Moons

Animate Titan, Rhea, Iapetus, Enceladus orbiting Saturn.

Animate Uranus's Moons

Animate Titania, Oberon, Umbriel, Ariel, Miranda orbiting Uranus.

Animate Neptune's Moons

Animate Triton, Nereid, and Proteus orbiting Neptune.

Animate Pluto's Moons

Animate Charon, Nix, Hydra, Kerberos, Styx orbiting Pluto.

Find When Planets Align

Find dates when two or more planets align in a straight line.

Find Dates of Solar Eclipse

Find dates when the solar eclipse happens.

Find Dates of Lunar Eclipse

Find dates when the lunar eclipse happens.

Find Your Age on Other Planets

Calculate your age based on the orbital period of other planets.

Create a Time Matrix

Represent a clock time as a matrix.

Create a Date Matrix

Represent a calendar date as a matrix.

Create a Time Vector

Represent a clock time as a vector.

Create a Date Vector

Represent a calendar date as a vector.

Visualize Time Series

Draw a time series chart.

Find Overlapping Times

Given a bunch of time intervals, find overlapping intervals.

Generate Overlapping Times

Generate a bunch of overlapping time intervals.

Generate Non-overlapping Times

Generate a bunch of non-overlapping time intervals.

Generate Random Time Intervals

Generate random clock time intervals.

Find Overlapping Dates

Given a bunch of date intervals, find overlapping intervals.

Generate Overlapping Dates

Generate a bunch of overlapping date intervals.

Generate Non-overlapping Dates

Generate a bunch of non-overlapping date intervals.

Generate Random Date Intervals

Generate random calendar date intervals.

Swap Clock Hands

Swap a clock's hour hand with minute hand.

Reverse Clock Time

Find the reverse of the given clock time.

Invert Clock Time

Find the inverse of the given clock time.

Shift Clock Time

Shift the given clock time by any time interval.

Change Clock Scale

Change the clock scale from 24 hours to any other hours.

Generate Valid Clock Times

Generate a list of valid clock times (for testing).

Generate Invalid Clock Times

Generate a list of invalid clock times (for testing).

Generate Valid Calendar Dates

Generate a list of valid calendar dates (for testing).

Generate Invalid Calendar Dates

Generate a list of invalid calendar dates (for testing).

Add Errors to Clock Times

Create errors in the given clock times (for testing).

Add Errors to Calendar Dates

Create errors in the given calendar dates (for testing).

Convert Date to Seconds

Convert a calendar date to seconds.

Convert Seconds to Date

Convert seconds to a calendar date.

Convert English to Crontab

Create a crontab expression from human language.

Convert Crontab to English

Rewrite a crontab entry into human language.

Find Week of the Month

Quickly find the week of the month of a calendar date.

Find Days Since the Start of Year

Quickly find how many days have passed since start of the year.

Find Days Till the End of Year

Quickly find how many days are left till the end of the year.

Find Days Till a Specific Date

Quickly find how many days are left till a specific date.

Convert Seconds To Minutes

Find how many minutes are in the given seconds.

Convert Seconds To Hours

Find how many hours are in the given seconds.

Convert Seconds to Days

Find how many days are in the given seconds.

Convert Seconds to Weeks

Find how many weeks are in the given seconds.

Convert Seconds to Months

Find how many months are in the given seconds.

Convert Seconds to Years

Find how many years are in the given seconds.

Convert Minutes to Seconds

Find how many seconds are in the given minutes.

Convert Minutes To Hours

Find how many hours are in the given minutes.

Convert Minutes to Days

Find how many days are in the given minutes.

Convert Minutes to Weeks

Find how many weeks are in the given minutes.

Convert Minutes to Months

Find how many months are in the given minutes.

Convert Minutes to Years

Find how many years are in the given minutes.

Convert Hours To Seconds

Find how many seconds are in the given hours.

Convert Hours to Minutes

Find how many minutes are in the given hours.

Convert Hours to Weeks

Find how many weeks are in the given hours.

Convert Hours to Months

Find how many months are in the given hours.

Convert Hours to Years

Find how many years are in the given hours.

Convert Days to Seconds

Find how many seconds are in the given days.

Convert Days to Minutes

Find how many minutes are in the given days.

Convert Days to Weeks

Find how many weeks are in the given days.

Convert Days to Months

Find how many months are in the given days.

Convert Days to Years

Find how many years are in the given days.

Convert Weeks to Seconds

Find how many seconds are in the given weeks.

Convert Weeks To Minutes

Find how many minutes are in the given weeks.

Convert Weeks To Hours

Find how many hours are in the given weeks.

Convert Weeks to Days

Find how many days are in the given weeks.

Convert Weeks to Months

Find how many months are in the given weeks.

Convert Weeks to Years

Find how many years are in the given weeks.

Convert Months to Seconds

Find how many seconds are in the given months.

Convert Months To Minutes

Find how many minutes are in the given months.

Convert Months To Hours

Find how many hours are in the given months.

Convert Months to Days

Find how many days are in the given months.

Convert Months to Weeks

Find how many weeks are in the given months.

Convert Months to Years

Find how many years are in the given months.

Convert Years to Seconds

Find how many seconds are in the given years.

Convert Years To Minutes

Find how many minutes are in the given years.

Convert Years To Hours

Find how many hours are in the given years.

Convert Years to Days

Find how many days are in the given years.

Convert Years to Weeks

Find how many weeks are in the given years.

Convert Years to Months

Find how many months are in the given years.

Convert a Bird's Age to Human Years

Find how old a human would be if he/she was a bird.

Convert a Human's Age to Bird Years

Find how old a bird would be if it was a human.

Convert Earth Time to Mars Time

Convert clock time on Earth to clock time on Mars.

Convert Mars Time to Earth Time

Convert clock time on Mars to clock time on Earth.

Convert Earth Date/Time to Stardate

Convert Earth time to Star Trek's stardate.

Convert Stardate to Earth Date/Time

Convert Star Trek's stardate to Earth time.

Generate Equal H:M:S Times

Print a list of clock times with hours equal mins equal secs.

Generate Equal Y-M-D Dates

Print a list of calendar dates with years equal months equal days.

Set Straight Clock Hands

Print a list of all clock times when hands are in a straight line.

Normalize Clock Times

Given clock times in various formats, convert them to one format.

Normalize Calendar Dates

Given calendar dates in various formats, make them the same format.

Rotate Clock Times

Cyclically shift HH, MM, SS time parts to the left or right.

Rotate Calendar Dates

Cyclically shift YYYY, MM, DD date parts to the left or right.

Freeform Time Calculator

Perform freeform clock time arithmetics.

Freeform Date Calculator

Perform freeform calendar date arithmetics.

Calculate Clock Sum

Find the sum of hours plus minutes plus seconds.

Calculate Calendar Sum

Find the sum of years plus months plus days.

Find Clock Sum

Find clock hand position so that hr + min + sec equals your value.

Find Calendar Sum

Find calendar date so that year + months + day equals your value.

Generate Clock Emojis

Print all clock icons from 00:00 to 24:00.

Create Zalgo Time

Generate date and time that only Zalgo can understand.


Subscribe!

Subscribe to our updates. We'll let you know when we release new tools, features, and organize online workshops.

Enter your email here


Feedback. We'd love to hear from you! 👋



Didn't find the tool you were looking for? Let us know what tool we are missing and we'll build it!