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Calendar date validator

World's simplest time tool

With this browser-based application, you can check if a calendar date exists and is correct. It tests if the date (and optional time) is well-formatted and also analyzes the limits of each date component. You can validate as many calendar dates as you want, choose the date status format, and print a descriptive error message. Created by computer nerds from team Browserling.
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Status Message
Print a short status of validated dates.
Detailed Message
Print a full description of the date error.
Calendar date validator tool What is a calendar date validator?
This is a quick online utility for validating calendar dates. The date validation algorithm that we implemented checks the format of a date, the components of a date, and verifies the date exists (for example, a leap year exists only once every 4 years). Once the validation is complete, it displays the result of the test on the screen. If the date is correct, the tool prints "Date is valid" (or just "Valid" if the short message form is enabled). If the date is incorrect, the tool prints "Date is invalid" (or "Invalid" in the short form). The first thing the program checks is that the date has a correct format and that all parts of the date contain only numbers. A valid full date format is "YYYY-MM-DD hh:mm:ss", however it can also be shortened to "YYYY-MM-DD hh:mm", "YYYY-MM-DD hh", "YYYY-MM-DD", "YYYY-MM", or just "YYYY". The program then checks each date component individually. The year must be at least -271821 (which is 271821 BC) and must not exceed 275760 (AC). For months, valid values are from 1 to 12. The dates in each month may differ, some months have 28 days, some 29, some 30, and some 31. The program checks the number of days in each month separately and displays an error if the number of days in that month are exceeded. If the input date has a clock time part, then it's also run through a number of checks. In particular, the maximum time is limited to 24:00:00, the minutes must not exceed 59m, and the seconds must not exceed 59s. To validate multiple calendar dates, enter them one per line into the input field. To get a shortened status check result use the "Short Status" checkbox option and to display a detailed description of the date error, use the checkbox "Show Detailed Error". Timeabulous!
Calendar date validator examples Click to use
Validate Calendar Dates
This example verifies two calendar dates. It checks the year, month, and date of each date and prints the result to the output text area. The first date is valid but the second date is invalid because there are a maximum of 12 months in a year but the date has "13" in the month component.
2022-02-15 2022-13-15
Date is valid. Date is invalid.
Required options
These options will be used automatically if you select this example.
Print a short status of validated dates.
Print a full description of the date error.
Date Check with Descriptions
In this example, we enter many calendar dates as the input and quickly analyze the validity of all dates. We also activate the verbose error option so that we can instantly find and fix errors in calendar dates.
2022-02-15 12:00:00 2017-10-12 1999-00-25 16:30 2026-11-30 02:36 2030-13-16 2023-11-20 01:26 2020-1-0 13:20:40 2021-07-24 2005-04-40 2001-02-18
Date is valid. Date is valid. Date is invalid. (Month is less than 1.) Date is valid. Date is invalid. (Month is greater than 12.) Date is valid. Date is invalid. (Day is less than 1.) Date is valid. Date is invalid. (Day is greater than 31.) Date is valid.
Required options
These options will be used automatically if you select this example.
Print a short status of validated dates.
Print a full description of the date error.
Multi-date Verification
In this example, we catch all the incorrect dates in a long list of dates. We use the short status output format and also add a short error description in parentheses to each invalid date.
2028-07-01-2 14:28 2001-01-28 14:10 2028y-10-14 10:00 -600000-01-01 1996-01-16 3000000-09-12 2025-02-31 12:00:00 2005-07-10 00:19:45 2027-15-09 02:80:33 2005-02-16 02:40
Invalid. (Valid format YYYY-MM-DD hh:mm:ss.) Valid. Invalid. (Valid format YYYY-MM-DD hh:mm:ss.) Invalid. (Date is too small.) Valid. Invalid. (Date is too big.) Invalid. (Feb 2025 consists of 28 days.) Valid. Invalid. (Minutes greater than 59.) Valid.
Required options
These options will be used automatically if you select this example.
Print a short status of validated dates.
Print a full description of the date error.
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://onlinetimetools.com/validate-calendar-date?input=2022-02-15%0A2022-13-15&show-details=false&short-status=false
All time tools
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Quickly visualize your life in weeks or months.
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 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 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.
Coming soon These time tools are on the way
Draw an Analog Clock
Draw an analog clock that shows particular time.
Draw a Digital Clock
Draw a digital clock that shows particular time.
Animate an Analog Clock
Create a GIF animation of an analog clock.
Animate a Digital Clock
Create a GIF animation of a digital clock.
Draw a Calendar
Draw a daily, monthly, or yearly calendar.
Draw a Lunar Calendar
Draw a calendar that shows moon phases.
Create an Animated Timer
Draw an animation that counts down (or up) time.
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 Current Year 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 Current Year as a Bar Chart
Visualize the current year as a bar chart.
Draw a Time Arrow
Visualize the given clock time as an arrow.
Visualize Time Intervals
Draw a visualization of multiple time intervals.
Visualize Time Series
Draw a time series chart.
Find Season by a Date
Print the season (winter, spring, summer, autumn) by a date.
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.
Generate Invalid Clock Times
Generate a list of invalid clock times.
Generate Valid Calendar Dates
Generate a list of valid calendar dates.
Generate Invalid Calendar Dates
Generate a list of invalid calendar dates.
Convert English to Crontab
Create a crontab expression from human language.
Convert Crontab to English
Rewrite a crontab entry into human language.
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.
Find Week of the Year
Given a calendar date, find which week of the year it is.
Find Day of the Year
Given a calendar date, find which day of the year it is.
Find Day of the Week
Given a calendar date, find which day of the week it is.
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.
Generate Palindromic Times
Print a list of symmetric clock times.
Generate Palindromic Dates
Print a list of symmetric calendar dates.
Generate Equal H:M:S Times
Print a list of clock times with hrs equal mins equal secs.
Generate Equal Y-M-D Dates
Print a list of calendar dates with yr equal mon equal day.
Calculate Clock Hand Angle
Find the angle between hour hand and minute hand.
Set Clock Hand Angle
Print a list of all clock times with a specific hand angle.
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.
Spell Clock Times
Write out clock times in full text format.
Spell Calendar Dates
Write out calendar dates in full text 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.
Create Zalgo Time
Generate date and time that only Zalgo can understand.