I went on for a while last night, but when the vote screen came up, all of the maps were expired as if they were all just played. I think it was just me considering that other players on at the time were voting and discussing which map to play when I couldn't. I came on again for some time today, and only two of the maps were available to vote for. I've never seen this happen before so I thought I'd post it here.
Odd, I've seen it before where people RTV'ed too much, but with the cooldown and addition of new maps I'd be surprised if that's possible these days.
I haven't touched my system clock in quite a while. Chrome told me that my clock was off a couple of days ago but I never changed anything.
For some background info; the way the it calculates on the client if a map is available is basically using timestamps which get localised accordingly. If you modify or change your system time - these will get thrown out of whack. I can remember at least one other case in the past of a person who had a similar issue and correcting the date / time fixed the issue. If Chrome is reporting it as well, I'd check to make sure the date / time is correct on your PC.