• *add_days Function
• *add_hours Function
• *add_minutes Function
• *add_months Function
• *add_seconds Function
• *add_years Function
• *days_between Function
• *hours_between Function
• *minutes_between Function
• *months_between Function
• *seconds_between Function
• *years_between Function
• a5_add_timestamp Function
• A5_CONVERT_DATE_STRING Function
• A5_CONVERT_DATETIME_STRING Function
• a5_embeddedcalendargenie Function
• a5_get_date_format Function
• A5_GETDATEHTML Function
• a5_gettimeformats Function
• a5_gettimevalue Function
• a5_normalizedate Function
• A5_RFC1123DATE Function
• A5_RFC822DATE Function
• A5_RFC850DATE Function
• A5_T_FROM_RFCDATE Function
• a5_time_format_help Function
• A5_TIMESTAMP Function
• ADD_BUS_DAYS Function
• ADDMONTHS Function
• ADDYEARS Function
• AGE Function
• BUS_DAYS_BETWEEN Function
• CDATE Function
• CDOW Function
• CMONTH Function
• CONVERT_TYPE Function
• CShortTime Function
• CTIME Function
• CTOD Function
• CTODT Function
• CTOT Function
• CYEAR Function
• Date and Time Conversion Matrix
• Date and Time Format Elements
• Date and Time Functions
• DATE Function
• Date_FirstDayOfMonth Function
• Date_FirstDayOfPreviousMonth Function
• DATE_FORMAT Function
• DATE_FORMATS_BUILT_IN Function
• date_from_utc_date Function
• date_is_anniversary Function
• date_is_in_last_month Function
• DATE_IS_IN_MONTH Function
• date_is_in_previous_quarter Function
• date_is_in_previous_week Function
• date_is_in_previous_year Function
• date_is_in_same_week Function
• date_is_in_this_month Function
• date_is_in_this_month_todate Function
• date_is_in_this_quarter Function
• date_is_in_this_quarter_todate Function
• date_is_in_this_week Function
• date_is_in_this_week_todate Function
• date_is_in_this_year Function
• date_is_in_this_year_todate Function
• date_is_today Function
• date_is_yesterday Function
• Date_LastDayOfMonth Function
• Date_LastDayOfPreviousMonth Function
• date_quarternumber Function
• date_quarterstartend Function
• date_to_utc_date Function
• DATE_VALUE Function
• DAY Function
• DAY_NUMBER Function
• DMY Function
• DOW Function
• DOW_ISO Function
• DTOC Function
• DTOS Function
• FixDateString Function
• FORMAT_DATA Function
• GetTimeZoneOffset Function
• GMT Function
• Holidays
• httpdate Function
• international_days_of_week Function
• international_months Function
• JDATE Function
• JTODATE Function
• MDY Function
• MONTH Function
• MONTH_END Function
• MONTH_NUMBER Function
• MONTH_START Function
• NOW Function
• NTH_DOW Function
• ODBC_DT_TO_D Function
• Predefined Date Formats
• ProgressTimed Function
• SCANTIME Function
• ShortTime_Extract Function
• STOD Function
• Time and Date Functions
• TIME Function
• time_gmt_to_local Function
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• TIME_VAR Function
• timez Function
• TOSECONDS Function
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• TZ_OFFSET_TO_C Function
• unixtimestamp_to_time Function
• WEEK Function
• WEEK_ISO Function
• WEEK_ISO_FULL Function
• WIN_TIME Function
• WMI_DATE_TO_TIME Function
• wmi_datetime_to_time Function
• YEAR Function
• YearStart_ISO Function

WEEK_ISO Function

Syntax

Arguments

dateDate

The date to be analyzed.

Returns

Week_NumberNumeric

Returns the ISO week number of the year where Monday is the first day of the week. Dates at the beginning or end of a calendar year may be included in the week for the previous or next year, respectively.

Description

Get the ISO calendar week number for a date where Monday is the first day of the week.

Discussion

The WEEK_ISO() function returns the ISO 8601 week number of the year where Monday is the first day of the week. Week numbers are 1 to 52 or 53. Part of week 1 may include dates from the previous calendar year. Part of week 52 or 53 may include dates from the next calendar year.

The first week of the year is calculated as the week containing the first Thursday of the calendar year. This implies the following:

• The first week is mostly within the calendar year.
• The first week contains January 4th.
• The first week starts with the Monday nearest January 1st.

The last week of the year is the week containing the last Thursday of the calendar year. The following statements are also true of the last week of the year:

• The last week of the year is mostly within the calendar year.
• The last week contains December 28th.
• The last week ends with the Sunday nearest to December 31st.

dim start as D = {1/1/2005}
? cdow(start)
= "Saturday"

? week_iso(start)
= 53

? week_iso(start+1)
= 53

? week_iso(start+2)
= 1

? cdow(start+2)
= "Monday"

See Also

• Date and Time Functions