It says right there. You have to write min 1000 subtitles or do 1000 segments in a drama, movie etc. during the below said period. PDT is California Time. Perhaps you have ongoing projects where you can sub or seg, if not, ask the channel manager or the respective language moderator of the drama you would like to contribute.
Or post that you would like to write subtitles here:
or find a project and contact CM or Mod here:
http://subber.viki.com/project_finder