Starting a diet is a very individual thing, but I like the Fall
Season, because:

1) Spring is too late to look good by late Spring, or Summer of that
same year.

2) Summer is WAY too late to look good for Summer of that year. Like
Spring, Summer is a great time to start a diet, as long as you know it
will be Fall, Winter, or next year, before you reach your goal weight.

3) Winter is busy with holidays, travel, (and traveling is not diet
friendly - lots of things beyond your control. You'll need to plan
ahead and be prepared for delays, having to eat out, less chances to
exercise, etc.)

Most dieter's can complete their diet in less than a year, and that
means a dieter starting in the Fall, will be looking good by Summer,
even if they haven't reached their goal weight yet.

Whether it's going to the beach, or just wearing lighter weight
clothes around the yard or park, it's nice to be able to see yourself,
and be seen, in your new, healthier, image.