What is `newtime` supposed to represent? Even with the comments, I can't make heads or tails of what the data is supposed to represent, so I can't evaluate it for correctness.

I guess I'm looking for a comment about how the federated backend formats the `custom_data`, with something like "issuedAt is the time in UTC when the token was issued, in YYYY-MM-DDHH:MM format", or something of that sort.

I'm a bit worried, looking at the current code, that shortly before or after midnight this is going to give you the wrong results (because UTC will be on one day, and we'll be on the previous day).