The + 1 needs to be removed as Sunday is 0, the DS3231 returns 0 for Sunday, using this + 1 puts Sunday to 1 on the PCF8563, which equates to Monday on the DS3231.
Also, please flag the PCF8563 to use 1900 year instead of 2000 to avoid any weekday weirdness when using NTP data.
IF the PCF8563 is set to use 1900, it can also lose the +/- 30, since both RTCs will be set using the 1900 year offset from NTP data.
WatchyRTC::read: tm.Wday = rtc_pcf.getWeekday() + 1;
The + 1 needs to be removed as Sunday is 0, the DS3231 returns 0 for Sunday, using this + 1 puts Sunday to 1 on the PCF8563, which equates to Monday on the DS3231.
Also, please flag the PCF8563 to use 1900 year instead of 2000 to avoid any weekday weirdness when using NTP data.
IF the PCF8563 is set to use 1900, it can also lose the +/- 30, since both RTCs will be set using the 1900 year offset from NTP data.