I wouldn’t bet my life savings on this, but it sure is interesting work that I read in Malcolm Gladwell’s Outliers: The Story of Success.
Gladwell basically states that if you were born in the summer months (for instance) and then ended up as the youngest of your cohort, you’re intellectually and physically not as mature, so you aren’t likely to be chosen for leadership positions or debates.
This is the reason why a lot of major league hockey players are born in the earlier months of the year — they’re bigger, even if it’s only by half a year.
According to Time magazine, the best and worst months to be the boss are:
The top 5 CEO-producing months are: March (12.53%), April (10.67%), November (10.67%), January (10.13%), October (9.87%).
Note that it says “CEO”, and not necessarily self-employed, or a freelancer.
In addition:
…although 8.16% of U.S. births happen in June, only 6.13% of CEOs were born in that month, while a mere 5.87% of CEOs were born in July, despite 8.75% of the U.S. population being born that month.
I also think that birth order in a family does matter to some extent — I’ve always wondered if being the youngest in a birth order made you more likely to take risks with your employment and to try things your older siblings wouldn’t.
It also depends on a whole bunch of other factors of course, but it is interesting nonetheless.

