WeBWorK Problems

Due Date shifts by plus or minus one hour upon uploading course

Due Date shifts by plus or minus one hour upon uploading course

by tim Payer -
Number of replies: 3
Has anyone else had the problem of the time of the due date for homework assignments shifting by plus or minus a single hour?

I had updated all the due date times for 11:59pm within the definition files of my Webwork course before archiving, downloading and then uploading them again for the new semester. However about 50% of the due times have shifted by plus or minus one hour. Many of the 11:59pm due dates have been shifted forward to 10:59pm still others have shifted to 12:59am the following day.
The dates are all consistent, it is just the jostle of the one hour that is puzzling.

What would cause this as the definition files all state 11:59pm as the time at which all these assignments should be due. ??

Tim
In reply to tim Payer

Re: Due Date shifts by plus or minus one hour upon uploading course

by Danny Glin -
This is a long-standing WeBWorK gotcha. It has to do with daylight savings time.

I'm guessing your set definition files include a time zone for each date, such as PDT or PST. If you enter a time in PDT when daylight savings is not in effect, it will convert it to PST, thus shifting it by an hour. Similarly when typing PST when DST is in effect.

I believe that now you can simply delete the time zone from such entries, and it will use the correct time zone based on your server settings.
In reply to tim Payer

Re: Due Date shifts by plus or minus one hour upon uploading course

by Alex Jordan -
I suspect Daylight Savings changes.

In your definition files, are the due dates like say:
10/04/2017 at 10:00pm PDT
?

Right now (January) is not Daylight Savings Time. Daylight Savings time zones still exist even though no one is using them this time of year. In my first example above, if I imported a set but now wanted it due in February, it would honor the 10:00pm PDT time. But then WeBWorK would translate that to PST. Unless I have things backwards, I think it would end up as 9:00pm PST.

Considering there was a time switch in the middle of your fall semester, and there will be one again in the middle of this coming semester, I can imagine the situation you describe. The early sets were in PDT in fall, but will be in PST for spring. So moved an hour back. The late sets were in PST in fall, but will be in PDT in spring, so moved an hour foreword. I'm guessing some sets in the middle of the semester maybe were in PST and will still be in PST this semester. (Or maybe PDT is the commonality?) And then there would be no change.

I think the solution is to not have time zones stored in the .def files. But I don't know that WW offers that option right now. If you created the .def files and then removed the timezones manually (or with sed or whatever), I think they would still import, and they would use whatever time zone is supposed to be in used on the relevant date.
In reply to Alex Jordan

Re: Due Date shifts by plus or minus one hour upon uploading course

by tim Payer -
Thank you Alex and Danny!

This makes sense as I was editing the files very close to daylight saving times back in November.
Yes I think that deleting the Time zone markers in the Definition file works.

I just deleted a homework assignment and then updated its corresponding definition file by deleting the time zone references.

Then I imported the homework set via the updated definition file.

The question is will these dates remain true once Day light saving comes on March 11th?

I will have to re-check these Definition files then.

thanks for the heads up.

Tim