What is the current week number?

The current ISO 8601 week number is dynamically calculated and displayed at the top of this page. ISO weeks start on Monday and week 1 is the week containing the first Thursday of the year.

How is the ISO 8601 week number calculated?

ISO 8601 defines the first week of the year as the week containing the first Thursday. Weeks start on Monday. A year can have 52 or 53 weeks.

How do I get the week number in Excel?

Use =ISOWEEKNUM(TODAY()) for the ISO week number. In older versions, use =WEEKNUM(TODAY(),21) where 21 means ISO-8601 (week starting Monday).

What Week Number Is It? | Current Week Number 2026 ᐅ

Programming Routines

Get the current ISO 8601 week number in your favourite language

                        Excel
                        Microsoft Excel / LibreOffice Calc
                    

=ISOWEEKNUM(TODAY())

Or in older versions: =WEEKNUM(TODAY(),21) where return type 21 is ISO-8601 (week starting on Monday).
In Excel 2007, use WEEKNUM(TODAY(),2) (2 = week starting Monday).
WEEKNUM(TODAY()) shows the week number with weeks starting on Sunday (return type = 1).

                        Sheets
                        Google Docs Spreadsheet
                    

=WEEKNUM(TODAY();21)

Type (here 21) is compatible with Excel/LibreOffice — 21 is ISO-8601.

                        PHP
                        PHP
                    

$weekNumber = date("W");

Or date("W", epoch) for other week numbers. Use capital W, not w.

                        Python
                        Python
                    

datetime.date.today().isocalendar()[1]

                        Perl
                        PERL
                    

my $weekNumber = POSIX::strftime("%V", gmtime time);

Replace time with other epoch/UNIX timestamps for other week numbers.

                        Java
                        Java
                    

Calendar now = Calendar.getInstance();
now.get(Calendar.WEEK_OF_YEAR);

Use WEEK_OF_YEAR in the Calendar class.

                        JS
                        JavaScript
                    

Date.prototype.getWeek = function () {
    var target  = new Date(this.valueOf());
    var dayNr   = (this.getDay() + 6) % 7;
    target.setDate(target.getDate() - dayNr + 3);
    var firstThursday = target.valueOf();
    target.setMonth(0, 1);
    if (target.getDay() != 4) {
        target.setMonth(0, 1 + ((4 - target.getDay()) + 7) % 7);
    }
    return 1 + Math.ceil((firstThursday - target) / 604800000);
}

var d = new Date();
alert(d.getWeek());

Extend the Date class using the above code.

                        C#
                        C#
                    

CultureInfo.CurrentCulture.Calendar.GetWeekOfYear(
    DateTime.Now,
    CalendarWeekRule.FirstFourDayWeek,
    DayOfWeek.Monday
);

See the ISO-8601 update on Stack Overflow.

                        MySQL
                        MySQL
                    

SELECT WEEKOFYEAR(NOW())

Replace NOW() with other dates, e.g. SELECT WEEKOFYEAR('2026-02-20').
You can also use the WEEK function with mode=3: SELECT WEEK(NOW(), 3).

                        PostgreSQL
                        PostgreSQL
                    

SELECT EXTRACT(WEEK FROM CURRENT_DATE)

                        MS SQL
                        MS SQL Server
                    

SELECT DATEPART(wk, GETDATE())

                        Oracle
                        Oracle
                    

SELECT TO_CHAR(SYSDATE, 'IW') FROM DUAL

IW: Week of year (1-52 or 1-53) based on ISO-8601.
WW: Week of year (1-53) where week 1 starts on the first day of the year (mostly NOT used).

                        iSeries
                        iSeries SQL
                    

SELECT WEEK(NOW()) FROM sysibm.sysdummy1

                        Obj-C
                        iPhone / Mac (Objective-C)
                    

[NSString stringWithFormat:@"Week %d",
  [calendar ordinalityOfUnit:NSWeekCalendarUnit
                      inUnit:NSYearCalendarUnit
                     forDate:date]];

                        Swift
                        iPhone / iOS / Swift
                    

let gregorian = NSCalendar(calendarIdentifier:
    NSCalendarIdentifierGregorian)!
gregorian.firstWeekday = 2 // Monday
gregorian.minimumDaysInFirstWeek = 4
let components = gregorian.components(
    .WeekOfYearCalendarUnit | .YearForWeekOfYearCalendarUnit,
    fromDate: date)
let week = components.weekOfYear
let year = components.yearForWeekOfYear

                        R
                        R
                    

lubridate::week()

                        Ruby
                        Ruby
                    

week_number = Time.now.strftime("%V")

Replace Time.now with Time.local(year, month, day) for other dates.
Formats: %U — week starting Sunday · %V — ISO-8601 · %W — week starting Monday.

                        Go
                        Go
                    

year, week := time.Now().ISOWeek()

                        Bash
                        Linux / Unix Shell (Bash)
                    

date +%V

Returns the ISO-8601 week number. See man date for more formats.

                        Lua
                        Lua
                    

Current_week = os.date("%V")

                        PowerShell
                        Windows PowerShell
                    

Get-Date -UFormat %V
# or
"{0:d2}" -f ($(Get-Culture).Calendar.GetWeekOfYear(
  $(Get-Date),
  [System.Globalization.CalendarWeekRule]::FirstFourDayWeek,
  [DayOfWeek]::Monday))

                        X++
                        X++ (Microsoft Dynamics AX)
                    

int weeknum;
weeknum = weekOfYear(today());

                        C/AL
                        C/AL (Microsoft Dynamics NAV)
                    

MESSAGE(FORMAT(CALCDATE('CW', TODAY), 0, '<week>'));

What Week Number Is It?

All Week Numbers 2026

Programming Routines