Yes you can. At full Moon, the Moon and Sun differ by exactly 12 hours in Right Ascension so that just when the Sun sets in the west, the Full Moon will rise in the east. The crescent phase you observe in the evening just after sunset is the Waxing Moon. Its bright crescent is pointed to the west in the direction of the Sun as it is setting. In the morning hours, you observe the waning crescent, and the crescent is pointed towards the east in the direction of the rising Sun. So, if you didn't know what time it was, if the crescent points east, it is a Waning Moon, and if it points west, it is a Waxing Moon.