FAA AIM does not mention a specific time for ATIS update. It says -
"ATIS broadcast shall be updated upon the receipt of any official hourly and special weather. A new recording will also be made when there is a change in other pertinent data such as runway change, instrument approach in use, etc."
At KDVT a new METAR is issued at 53 minutes past the hour and the ATIS time is usually 53 minutes past the hour. I assume it is the issuance of the new METAR that drives the ATIS update which is as stated in the AIM.