Martijn How to fix a problem with your certificates expiring? Just change your computer date to before they expire! (This is not actual advice, this is Reddit advice.) thenextweb.com/app...

Mark Dain My standard practice nowadays is to buy a certificate 2 weeks before it expires, then sit on it for a week (to build up tolerance to clock drift like this). If your clock is more than 1 week out (either way) you'll run into problems but in my experience you almost never drift that much. So 1 week buffer on either side works well for me.