weekdate_iso

Syntax:

     time = weekdate_iso( year, week [, day] )

This function converts from the year, week, day components of a date in ISO 8601 "week date" format to the calendar date as a time in seconds since the epoch date 1 Jan 1970. Note that the nominal year in the week date system is not necessarily the same as the calendar year. The week is an integer from 1 to 53. The day parameter is optional. If it is omitted or equal to 0 the time returned is the start of the week. Otherwise day is an integer from 1 (Monday) to 7 (Sunday). See tm_week for additional information on an inverse function that converts from calendar date to week number in the ISO standard convention.

Example:

     # Plot data from a file with column 1 containing ISO weeks
     #     Week     cases  deaths
     #     2020-05    432       1
     calendar_date(w) = weekdate_iso( int(w[1:4]), int(w[6:7]) )
     set xtics time format "%b\n%Y"
     plot FILE using (calendar_date(strcol(1))) : 2   title columnhead