--- title: "GetFirstDayOfIso8601WeekOfYear" slug: "getfirstdayofiso8601weekofyear" updated: 2024-05-04T19:40:18Z published: 2024-05-04T19:40:18Z canonical: "help.mail-and-deploy.com/getfirstdayofiso8601weekofyear" --- > ## Documentation Index > Fetch the complete documentation index at: https://help.mail-and-deploy.com/llms.txt > Use this file to discover all available pages before exploring further. # GetFirstDayOfIso8601WeekOfYear ### General This function returns a [Date-Time](/release34/docs/date-time) that represents the first day of a given week of year according to ISO 8601. ### Syntax You can call the GetFirstDayOfIso8601WeekOfYear function using the following syntax: GetFirstDayOfIso8601WeekOfYear Function Syntax GetFirstDayOfIso8601WeekOfYear(, ) The parameters of the function are: | Name | Description | | --- | --- | | year | The year to which the week of year belongs. | | weekofyear | The week of year for which to return the first day. | | Examples | | | The following expression returns a [Date-Time](/release34/docs/date-time) that contains the first day of the week of year *37* of *2021*: | | GetFirstDayOfIso8601WeekOfYear Function Example GetFirstDayOfIso8601WeekOfYear(2021, 37)