CUCaTS
Puzzlehunt 2014
h(x) = df5130895b1189bf3fa1ec4dced09baf744bf41adb479e8803900c5266ba9ca0
author: unknown
h(x) looks like a cryptographic hash, and refreshing the page shows it changes every 5s. We find that the SHA256 hash of the unix time (floored by 5 seconds) gives us the same hash. Thus the answer is the current unix time (and values within ± a minute are accepted).