Change join date format?

[Fulla]

Hi, the user join date in the postbit appears as MM/YY and I want it to show the day as well, is there any way to do that?
I tried editing the postbit and use the same format as the memberinfo join date but without any success.

[King Kovifor]

Moved to correct forum.

[Dismounted]

vBulletin Options > Time/Date Options

[Fulla]

thanks