Setting Day marks the opening of the spring lobster season on P.E.I. When the traps are set in the water.
In my area, the lobster boats with their lobster traps wait in the Montague Harbour for SETTING DAY to start.
About 1200 Island lobster fishers work out of PEI's 45 ports; many fishers are carrying on a tradition that goes back generations. The Island's lobster fishers work on the water for two months in one of PEI's two lobster seasons and the first day of the season is known as Setting Day.
Source
Lobster traps lined up on the wharf
Like farmers the fisherman depend on the weather for harvesting their catch. Setting has been delayed from April 29 until May 3 this year because of bad weather and some dredging of the harbours had to be done.