Complex sentence: This is done because regional tickets are not for a particular date or time but are valid for some months (two months until 1st August, 2016)-the date/time stamp is to show that the ticket cannot be reused.
Split into simpler sentences: This is done because regional tickets are not for a particular date or time but are valid for a period (two months for tickets bought before 1 August 2016). The date/time stamp is to show that the ticket cannot be reused.