strftime date without leading zeros code example
Example: strftime date without leading zeros
Actually I had the same problem and I realized that, if you add a hyphen between the % and the letter, you can remove the leading zero.
For example %Y/%-m/%-d.
This only works on Unix (Linux, OS X), not Windows (including Cygwin). On Windows, you would use #, e.g. %Y/%#m/%#d.