Altered date function calls on cal to new interface cal.dtz

[tobiasreischmann]

See https://bugzilla.mozilla.org/show_bug.cgi?id=1408662 for details.

[advancingu]

Thanks!
Are these the only places where these changes were needed?

[tobiasreischmann]

I searched the whole code for all occurrences from the list from the top post of the bug report. Thus, I would assume those are the only places, yes.

[advancingu]

Thanks!