PAGRNE DESIGNPagani Design Herren-Armbanduhr, automatisch, mechanisch, GMT, 42 mm, Sport, wasserdicht, Edelstahl, Saphirglas

Q: 42 or 39.7? Even the answers to the previous questions are inconsistent.

It's definitely a larger watch, 42 for sure.

Q: Why the date/calendar never change?

If your "date" does not change after a 24-hour rotation, there may be an issue with the date disk in the movement. You should contact Amazon and return the watch for a refund. However, you can also contact the vendor and let them know what the problem is, then see if they would send you a replacement.