Remove leap year handling
Reasons:
- All other tools around (streamflow generator) don't use leap years.
- Date handling is OK from 1600 and it's a limitation for using more than 8000 years.
- Conversions are painful and source of bugs.
Bonjour, la 2ème lettre d'information du projet de forge INRAE est disponible à cette adresse : https://forge-inrae.pages.mia.inra.fr/www/post/2024-02-14-info-lettre-2/
Reasons: