Concrete's ability to set is determined by the amibent air temp. It takes about 3 times as long for it to set at 0C than at 20C. It will start to freeze below -2C and will not set at all below -7C, with the possibility of a up to 50% reduction in 28 day strength if that occurs...not something you want in PQ (Pavement Quality) mix for a/c aprons.
So, yes, if someone was faffing about delaying a decision and moving the build window into the winter months then this isn't a surprising result.