I have TB in american english, but I hate american english date format (mm/dd).
To fix this ugly, terrible, disgusting way to show dates, I tried unsuccessfully to:
- go in TB about:config
- intl.locale.requested = it, en-US
The only way, then, seemed to set whole TB in Italian (or in an other not-english language that has dd/mm).
But there is a real possibility: use en-GB instead of en-US: and so you have both, english and dd/mm as date format.