This was officially announced in the SC Announcement, but I am copying here also:
Due to the need to update the software used in our polling system before this election (not after, as was expected), and the time-frame needed to complete that update, the polls for the 21st RA and Chancellor election will open on Saturday May 17th and close on Saturday May 24th.
Polls will remain open the required 168 hours, the only change is in the date they open.
This means campaigning can continue for an additional week.
Callipygian