The duration of a submission varies a lot. The complexity of your character, your alignment, your choice of race, Deity, and all other character traits can add or decrease the time it takes to get approved. (generally...)
If you're the generic farm boy, the approval is a one shot deal. If you're the Half-Drow Half-Human son of the Matron of House Vixlan, who is cast unto the surface seeking the sacred dagger of Umlaut to wipe clean the scourge of your mother's infinite supply of thralls, then perhaps it may take a wee bit longer.
Also, a tip about submissions - treat it like an essay about your character. My best advice is to write out the main points of the character, their personality traits, and finally the smaller details. Then you can easily craft a well-written and easy-to-approve submission, using the notes as a guide.