Quarter

Quarter means a 3-month period; the first quarter concludes on the last day of the last full month during the 180 days following initial startup.

Source

40 CFR § 60.481


Scoping language

As used in this subpart, all terms not defined herein shall have the meaning given them in the Act or in subpart A of part 60, and the following terms shall have the specific meanings given them.

Is this correct? or