I'm sure it's an easy question to answer but I've really not understood something and it's doing my head in:

The O6 have been off the island for 3 years since escaping from the boat, but the peeps who stayed on the island have been 'leaping' since they left. We've only really seen them leaping this season so it really only seems like it's been a few days, but have they been leaping for 3 years??

I'm having trouble relating the timeline of the people on the island compared to those who got off. Any help?