California Code, Government Code - GOV § 82046

(a) “Period covered” by a statement or report required to be filed by this title, other than a campaign report, means, unless a different period is specified, the period beginning with the day after the closing date of the most recent statement or report which was required to be filed, and ending with the closing date of the statement or report in question.  If the person filing the statement or report has not previously filed a statement or report of the same type, the period covered begins on the day on which the first reportable transaction occurred.  Nothing in this chapter shall be interpreted to exempt any person from disclosing transactions which occurred prior to the effective date of this title according to the laws then in effect.

(b) “Period covered” by a campaign report required pursuant to Sections 84200, 84200.5, 84202.3, and 84202.7 means, unless a different period is specified, the period beginning the day after the closing date of the most recent campaign report which was required to be filed and ending with the closing date of the statement in question.  If a person has not previously filed a campaign report, the period covered begins on January 1.