wrong day for DST change

[dobryj]

Hi!

today I detect, that time from ezTime library is invalid. After some investigation I found, that problem is that ezTime thing that I need CET time, but today is last day with CEST
I am set Olsen format "Europe/Prague"
It is converted to POSIX correctly : "CET-1CEST,M3.5.0,M10.5.0/3"
This is correct. Problem is that today (27-Oct-2018) is last weekend on October but not .0 ( =Sunday)
ezTime show Time: Saturday, 27-Oct-2018 12:08:32 CET

Any idea?

[ropg]

Ouch, see the same problem here. Looks like something is off. I will look into that urgently later today or tomorrow...

[chinswain]

Same for gb timezone:

UTC: Saturday, 27-Oct-2018 12:00:38 UTC
New Zealand: Sunday, 28-Oct-2018 01:00:38 NZDT
United Kingdom: Saturday, 27-Oct-2018 12:00:38 GMT
Local (GeoIP): Saturday, 27-Oct-2018 12:00:38 GMT

[dobryj]

I found reason.
Problem is on dst_start and dst_end equations.
Hotfix is +1 on "dow" in library (line 741+742) like

time_t dst_start = ezt::makeOrdinalTime(start_time_hr, start_time_min, 0, start_week, start_dow+1, start_month, tm.Year + 1970);
time_t dst_end = ezt::makeOrdinalTime(end_time_hr, end_time_min, 0, end_week, end_dow+1, end_month, tm.Year + 1970);

In detal it is problem on weekday numbering. In ezTime function UTC.weekday() return sunday=1. But posix rule use sunday=0.

[ropg]

I found reason.
Problem is on dst_start and dst_end equations.
Hotfix is +1 on "dow" in library (line 741+742) like

time_t dst_start = ezt::makeOrdinalTime(start_time_hr, start_time_min, 0, start_week, start_dow+1, start_month, tm.Year + 1970);
time_t dst_end = ezt::makeOrdinalTime(end_time_hr, end_time_min, 0, end_week, end_dow+1, end_month, tm.Year + 1970);

In detal it is problem on weekday numbering. In ezTime function UTC.weekday() return sunday=1. But posix rule use sunday=0.

You're absolutely right: a bug indeed, and the fix is exactly as you describe. I will release a new version of ezTime later today.

[JasXSL]

I'm getting a DST issue here too. Using tz.setLocation(F("Europe/Stockholm")) it's giving me CEST a week in advance. Maybe because this year there are 5 Sundays in March?

[ropg]

Are you using version 0.7.10 ? It should be fixed there.

[JasXSL]

Yep that update fixed it, thanks