F3 "Day Counter" Innacurate

I had just began a new Skyblock game when I noticed, after the second night, that the day counter was at "Day 17".

This may just be a problem with Skyblock, but I encountered a similar issue on a vanilla map: I was playing in a snapshot survival world and had been at around day 40 when last checked. I checked not too long after and saw the day counter reading in the high 60s.

Steps to reproduce:

1. create a survival world
2. pass the time for a little bit, perhaps 2-3 days (I am unsure if the /time command would mess with the bug)
3. check if there is a discrepancy in the days counted on the F3 screen and how many days have truly passed.

Further testing may be needed.