i know its a [censored] question, but can someone explain when is the correct time to sign up for the catacombs? someone in game told me you have a week from monday or something but its every other week. i really dont even remember what they said anymore.
Your friend is correct. There is a two week period over which the competion runs. The first week (Monday - Monday) you sign up and choose who you wish to fight for (Dawn/Dusk - visit the corresponding priest in town). The second week will announce which side won (Dawn or Dusk) and if you fought for the winning side the previous week you can still go into the catas to level/party. If not you will be unable to enter until the following Monday when the competition begins again.
This is a simplistic explanation and a more detailed description is in the Seven Signs section in the library (left) and is all explained clearly there.