online chess time control problem

so i was playing 2 guys in online chess , both had their time goes under 15h , then its back to 3 days again O_o is that some sort of cheating ?

Vacation maybe? or internet bug? 

Sounds like they went on vacation and came back.  Not cheating but if they do it repeatedly it's considered vacation abuse and they could have their accounts restricted or even terminated.  Let me get a link:

http://support.chess.com/Knowledgebase/Article/View/26/0/how-does-vacation-work--how-much-time-do-i-get

Here's the abuse link:

http://support.chess.com/Knowledgebase/Article/View/104/0/what-is-vacation-abuse

i dont think its vacation i play other players who are on vacation , and its clearly written " on vacation " with the remaining time ( 43 min ) , while one of these guys play his moves each day ( approximatively ) his time was down to 15 h , then poof 3 days again

again he got down to 2 days then he is back to 3 days again :|