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Week of year calculator

World's simplest time tool

With this browser-based application, you can find the week of the year for any calendar date. The program counts the number of weeks that have passed since the 1st of January and shows the week number for your given date. You can find the week counter for several dates if you enter them into the input field, each on a separate line. You can also switch between a numeric and textual output format. Created by computer nerds from team Browserling.
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Week Output Format
Print the result in a text form with the week number as an ordinal number and the original date included.
Week of year calculator tool What is a week of year calculator?
This is a quick online utility for calculating the week number for any calendar date. When you enter a date, it determines what its week number is. For example, the date "2022-01-20" is the 2nd week of the year so the output is "2"; and the date "2023-10-01" is the 40th week of the year, so the output is "40". A common calendar year consists of 52 weeks and 1 extra day and a leap year has 52 weeks and 2 extra days. We use a simple mathematical algorithm to find the week of the year. Our program calculates how many days have passed from the beginning of the year to the specified date and then divides the number of passed days by 7 (the number of days in a week). For example, for the date "2023-10-01" there have been 274 days passed from "2023-01-01" (the beginning of the year), so to get the week number, we divide 274 by 7 and get 40, which means its the 40th week of the year. The input field can process multiple calendar dates at once if you just enter them separated by a newline. You can also change the format of the calculated results using the checkbox in the options. If the checkbox isn't activated, you'll get a purely numeric result "40" for the date "2023-10-01". If the checkbox is activated, you'll get a full sentence as the output that says: "2023-10-01 is 40th week of the year.". If you want to know what day of the year a given date falls on, then you can switch to our find day of the year tool. Timeabulous!
Week of year calculator examples Click to use
Project Deadline in Weeks
In this example, we enter the deadline date "2022-10-15" for a project that we started in early January of 2022. We use our utility to calculate how many weeks in total we can spend working on the project. In the output, we get the number 42, which means that has to be delivered by the forty-second week of the year.
2022-10-15
42
Required options
These options will be used automatically if you select this example.
Print the result in a text form with the week number as an ordinal number and the original date included.
Week Numbers of Quarters
In this example, we determine which week of the year the 1st, 2nd, 3rd, and 4th quarter ends on. We input four dates and find that the first quarter ends on the 13th week, the second on the 26th week, the third on the 40th week, and the fourth on the 53rd week. We enable full-text output format, which also includes the original calendar dates and makes it easier to read the information.
2024-03-31 2024-06-30 2024-09-30 2024-12-31
2024-03-31 is 13th week of the year. 2024-06-30 is 26th week of the year. 2024-09-30 is 40th week of the year. 2024-12-31 is 53rd week of the year.
Required options
These options will be used automatically if you select this example.
Print the result in a text form with the week number as an ordinal number and the original date included.
Prime Weeks
This example shows the starting dates for the weeks that are prime weeks. Prime weeks mean that their count in a year is a prime number. The first prime week is the 2nd week that starts on the 8th of January, then the next one is the 3rd week that starts on the 15th of January, then the 5th week that starts on the 29th of January, and so on.
2000-01-08 2000-01-15 2000-01-29 2000-02-12 2000-03-11 2000-03-25 2000-04-22 2000-05-06 2000-06-03 2000-07-15 2000-07-29 2000-09-09 2000-10-07 2000-10-21 2000-11-18 2000-12-30
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53
Required options
These options will be used automatically if you select this example.
Print the result in a text form with the week number as an ordinal number and the original date included.
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/find-week-of-year?input=2022-10-15&print-date=false
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Quickly convert time in 12 hour format to 24 hour format.
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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.
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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.
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.
Animate a Broken Clock
Create a GIF animation of a clock that's broken.
Draw a Calendar
Draw a daily, monthly, or yearly calendar.
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.
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 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.
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.
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.
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.
Visualize Time Intervals
Draw a visualization of multiple time intervals.
Visualize Date Intervals
Draw a visualization of multiple date intervals.
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.
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 (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.
Generate Palindromic Dates
Print a list of symmetric calendar dates.
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.
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Generate date and time that only Zalgo can understand.