> [...] discover that WhatsApp doesn’t work on it due to a weird message > "Your phone date is inaccurate! Adjust your clock and try again." > I have no idea what do date issues have to do with not starting WhatsApp but fixing the date and time didn’t help [...]

Some network protocols use timestamps for security. For example, OAuth 1.0 HMAC used timestamps as part of its mechanism for preventing replay attacks.

I have no particular insight into what WhatsApp is doing, though.