You must complete the initial compliance demonstration for the initial compliance period according to the requirements of § 63.4151. The initial compliance period begins on the applicable compliance date specified in § 63.4083 and ends on the last day of the first full month after the compliance date. If the compliance date occurs on any day other than the first day of a month, then the initial compliance period extends through the end of that month plus the next month. The initial compliance demonstration includes the calculations according to § 63.4151 and supporting documentation showing that the organic HAP emission rate for the initial compliance period was equal to or less than the applicable emission limit in § 63.4090.