iso week number in Eggplant

Eggplant Functional
1

Hi,
is there a quick way to get the iso week number in Eggplant ?
Thanks

2

There seems to always be something new that people want to do with dates! :slight_smile:

No, the ISO Week number isn’t something that’s built into SenseTalk (yet!), but in searching to see what this was, I found an algorithm to calculate it posted by Rick McCarty. I implemented his approach in this weekDate function:

to handle weekDate of aDate
	if aDate is empty then set aDate to the date else set aDate to date(aDate)
	set y to year(aDate)
	set m to month(aDate)
	set d to day(aDate)
	set leapYear to (y mod 4 = 0 and y mod 100 <> 0) or y mod 400 = 0
	set leapPrev to ((y-1) mod 4 = 0 and (y-1) mod 100 <> 0) or (y-1) mod 400 = 0
	set DayOfYearNumber to dayOfYear(aDate)
	set Jan1Weekday to dayOfWeek(y&"-01-01")
	if Jan1Weekday is zero then set Jan1Weekday to 7
	set Weekday to dayOfWeek(aDate)
	if Weekday is zero then set Weekday to 7
	if DayOfYearNumber <= (8 - Jan1Weekday) and Jan1Weekday > 4 then
		set YearNumber to y - 1
		if Jan1Weekday = 5 or (Jan1Weekday = 6 and leapPrev) then
			set WeekNumber to 53
		else
			set WeekNumber to 52
		end if
	else
		set YearNumber to y
		set i to (if leapYear then 366 else 365)
		if (i - DayOfYearNumber) < (4 - Weekday) then
			add 1 to YearNumber
			set WeekNumber to 1
		end if
	end if
	if YearNumber is Y then
		set J to DayOfYearNumber + (7 - Weekday) + (Jan1Weekday - 1)
		set WeekNumber to J div 7
		if Jan1Weekday > 4 then subtract 1 from WeekNumber
	end if
	return (YearNumber, WeekNumber, Weekday)
end weekDate

This function returns a list containing the year number, the week number, and the day of the week for any date that is passed to the function. If you don’t pass a date it assumes the current date.

I’ve also uploaded a script file containing a slightly modified version of this handler and a couple of additional handlers to return just the week number and to return the date in a standard ISO 8601 Week Day format. The script includes some test code that produces this output:

2008-09-16 is 2008-W38-2
2005-01-01 is 2004-W53-6
2005-01-02 is 2004-W53-7
2005-01-03 is 2005-W01-1
2005-12-31 is 2005-W52-6
2007-01-01 is 2007-W01-1
2007-12-30 is 2007-W52-7
2007-12-31 is 2008-W01-1
2008-01-01 is 2008-W01-2
2008-12-28 is 2008-W52-7
2008-12-29 is 2009-W01-1
2008-12-31 is 2009-W01-3
2009-01-01 is 2009-W01-4
2009-12-31 is 2009-W53-4
2010-01-01 is 2009-W53-5
2010-01-02 is 2009-W53-6
2010-01-03 is 2009-W53-7
2010-01-04 is 2010-W01-1

I don’t guarantee that this will produce the correct results in all cases, but it seems to be working as expected. Good luck!

3

Thank you Doug,
I just had to modifiy something in order to avoid an error message.
I replaced all the “to hanble handleName of aParameter” with “to handle handleName(aParameter)” and it works perfectly (up to now).

Thanks again.

4

Oops! Allowing the “of” syntax in “to handle” may be a recent addition that hasn’t made it into Eggplant yet… I should have been more careful about which version I tested that in. I’m glad you figured out how to make it work!