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.