The signs say 28th of the month and 26th of the month but reset on the 24th of last month. I don't know what to believe anymore! This is on main. Main North reads 26th.
Yes, the schematic we use for mining spawn has updated signs stating the 26th, the wiki is also updated for all mentions of mining reset ETA. I also checked the current mining spawn, it looks like this was only an issue on the first sign, the rest of them say the 26th. I believe manually edited these signs for this month after confirming the new ETA is the 26th, probably missed that one.
