I’ve updated the swRTC library to the revision 1.2.2 after an user of it informed me that the function getWeekDay(), that returns a value indicating the number of the weekday of the date itself, was wrong. Starting from there I’ve found that the value of the timestamp (the number of seconds since a specific date) wasn’t considering the fact that, in case of leap years, the leap day wasn’t reached until february, 29th, so for the dates before that day it shouldn’t be calculated.
The new version is available for download from this page.