"It is half past one."
Translation:डेढ़ बजा है।
I overlooked this first, too, but: in these sentences it is important to match बजा / बजे with है/हैं. Entering डेढ़ बजे है was rejected (and I thought 'damn, is it बजा here again'), but no, next time I tried डेढ़ बजे हैं and it was also accepted.
So: If you use बजा (which is singular) then you have to match it with है (which is used for singular nowns). If you use बजे (which is plural) then you have to match it with हैं (as usual for plural nowns).
डेढ़ itself can be both used with बजा or बजे, but you have to keep an eye on है/हैं to get the sentence right.