Not from Thanksgiving through the end of January: people generally spend their money on other things until Christmas, and then they pay for their purchases—at least partially—the next month…

Also avoid the end of the year because fonts released then will not be considered for annual lists, which are compiled earlier.

Never in summer. Best time to me: February and March or end of August to end of October.

Don't designers -who seem to have less family than most professions- buy themselves gifts for Xmas?

February and March

Not in the US. Taxes!

I think the best time to release is... right now. The earlier it hits the ground the sooner it will make more money for you. And you can start worrying about your next one.

hhp

hhp - agree completely!

perhaps what matters more is choosing when to promote.