Normally, the daily reward has a set cover every 15 days, sometimes moving it back or forward one day when it overlaps one of the other scheduled rewards (heroic tokens or 25 HP). Day 310 was an Invisible Woman cover, day 325 is a heroic token, and days 324 and 326 look to be random.
We hit a stretch once before where reward covers weren’t scheduled, and devs had to update the schedule. It looks like it’s happening again.
Also, this is a good time to put something really nice in the list on day 365.
