I did not see a time limit. I assume 24 hrs? I have done two SS 1000, one on the bandit and one on the wee, in 15 hrs. Trick is to keep moving at a reasonable pace, stay hydrated, and make sure your bike is comfy. A sore azz can be a real pain! If you have a riding partner bike coms are really nice! Or just have one for the radio.
'01 KLR 650, '09 Suzuki DL650, '08 Suzuki Bandit 1250, '16 CRF1000L, '09 KLX 250s