HTC said a while back that the Android 4.3 update would hit all US HTC One handsets by the end of September. That obviously didn't happen, but the company wasn't too far off in the case of Sprint. That version of the device is getting the update today.
Good news! 4.3 will begin to push to HTC One users on Sprint today.
— Jason Mackenzie (@JasonMacHTC) October 2, 2013