Yeah

I tried the fix proposed by spitzak. It seems to work.

Thanks everybody for comments.

Jer'

Le mercredi 31 mars 2021 à 18:13:08 UTC+2, spitzak a écrit :

A real quick fix is to add 12 hours to the time so it figures out what day contains noon+n*24 rather than midnight+n*24, which will not change when daylight savings time turns on/off.

On Wed, Mar 31, 2021 at 6:58 AM :

https://github.com/nikego/Fl_Calendar 

As someone else suspected, it might have to do with daylight saving
changes. Similar issues appear around end of October.

A quick glance at Nikita's code shows:

#define SECSPERDAY (60 * 60 * 24)

Day calculations in update_table() are performed by adding SECSPERDAY as delta seconds and using localtime() to find the date. This will be thrown off by time changes.