You must complete the initial compliance demonstration for the initial compliance period according to the requirements in Sec. 63.3521. The initial compliance period begins on the applicable compliance date specified in Sec. 63.3483 and ends on the last day of the 12th month following 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 12 months. The initial compliance demonstration includes the calculations according to Sec. 63.3521 and supporting documentation showing that, during the initial compliance period, you used no coating with an organic HAP content that exceeded the applicable emission limit in Sec. 63.3490 and you used no thinners that contained organic HAP.