Its my challenge for my brithday that I'm aiming to do 1 mile, 1609m i think, in about 20minutes.
I'm not an expert at training but i've set my self a list of goals that i'm trying to complete.

1 length   - 15s
2 lengths - 30s
4 lengths - 60s

8 lengths - 2 minutes

The first 4 are complete, and the next step will be to do multiple lots of 10 lengths in 2mins 30s