The honest answer is....it depends.
In 22 years, I've picked up almost 1300 days at sea.
But.
Some years have been gogogo, with 8+ months off the wall.
Others, such as in a refit time, have been mostly alongside.
Sometimes you get a shore posting, and you'll be on land for a bit, but when a ship sails, and is short, they might come looking for you to backfill.
Note, the 1300 days is "Days at sea"....not days away from homeport. Coming alongside in a foreign port for a weekend doesn't count as a sailing day, but you're still away from home.
The worst schedules are those in a trial period for a ship. You're in and out, late, early, 3 days here, 5 days there, the plan changes if there's something that doesn't go right.
The times I prefer are the longer sails. Give me a 6 month trip, let me get into a routine. Let my family get into the routine of me being gone.
So....it all depends on what ship you're on.
NS