F_GetWeekOfTheYear

The function returns the calendar week number for a specified date according to the DIN 1355 / ISO 8601 standard.

• The first calendar week is defined as the first week that contains a minimum of four days of the new year (DIN 1355 / ISO 8601).
• The calendar weeks start on a Monday. Each calendar week contains 7 days.
• The returned value in the first calendar week has the number 1.
• 29, 30 and 31 December may belong to the first calendar week of the following year.
• 1, 2 and 3 January may belong to the last calendar week of the previous year.

FUNCTION F_GetWeekOfTheYear : WORD

VAR_INPUT
    in : DT;
END_VAR

Example:

PROGRAM MAIN
VAR
    dtNow      : DT := DT#2008-03-17-12:00;
    weekOfYear : WORD;
END_VAR

weekOfYear := F_GetWeekOfTheYear(dtNow);

The result is 12.