Please indicate in-game that the deadline for mission completion is midnight UTC, and not local time. The current missions don’t show this deadline anywhere!
As you can imagine, I completed the Jan 2023 monthly challenge during Jan in my timezone, not UTC. I got an email saying the monthly challenge was completed, but I don’t have the badge in game. So, I’d also request that Zwift please work on producing consistent behavior between the email service that says, “You did it!” and the game badges, which say, “You didn’t do it!”
Talking to support, I will not get the badge for Jan (/shrug), but communicating to users in game what the deadline is would be great!