This just popped into me frond.
Answer: For me it depends. Has the player had time to actually read my history handout (HH)?
If not, then I'll let the player create and start playing the character, allowing up to a week.
If they have read the HH, but no time to actually work on the CG (Character Background), again up to a week, but perhaps create a blurb, after PCGen is finished.
If they have read the HH and had a day, or two, or three, then I expect at least a few paragraphs, up to a page, or two, or three.
rmfr