These dates are also found on the PDC's Calendar of Events.  (Printer-friendly version)

Key dates for 2022 special elections.

Key dates for 2021 special elections are also available.

Within 2 weeks of becoming a candidate Register the campaign (File a C-1) (non-incumbents also file an F-1)
January 11 File a C-3 for each deposit made in the previous month and a C-4 report that covers the period through Dec 31
February 10 File a C-3 for each deposit made in the previous month and a C-4 report that covers the period through Jan 31
March 10 File a C-3 for each deposit made in the previous month and a C-4 report that covers the period through Feb 28
April 12 File a C-3 for each deposit made in the previous month and a C-4 report that covers the period through Mar 31
May 10 File a C-3 for each deposit made in the previous month and a C-4 report that covers the period through Apr 30
May 17-21 Declaration of candidacy filing week
June 1 Begin filing C-3 reports weekly, each Monday, for deposits made during previous 7 days (Monday through Sunday)
June 10 File month C-4, if necessary, that covers the period through May 31
June 21 Last day before primary election to change from mini to full reporting without special circumstances (See WAC 390-16-125)
July 13

Candidates appearing on the primary election ballot file a C-4 that covers the period June 1 through July 12.

Candidates not on the primary election ballot file monthly reports in June, July and August. These reports due on the 10th of the following month.
July 24 - Aug 2 Campaign books open for public inspection
July 27 Candidates appearing on the primary election ballot file a C-4 that covers the period July 13 through July 26
July 27 - Aug 2

Special reports due if candidate receives contributions of $1,000 or more from a single source.

NOTE: Does not constitute authority to exceed applicable local or state contribution limit
AUGUST 3 PRIMARY ELECTION DAY
August 31 Last day before general election to change from mini to full reporting without special circumstances  (See WAC 390-16-125)
September 10

Post-primary C-4 due that covers the period July 27 through August 31

Candidates not on the primary election ballot file a report for the month of August
October 12 21-day pre-general C-4 report due - report for the period Sept 1 through Oct 11
October 12 - November 1
  1. Special reports due if candidate receives contributions of $1,000 or more from a single source
  2. Unless the contribution is from the state committee of a bona fide major or minor political party, a candidate may not receive contributions from a single source exceeding $5,000 in the aggregate.  
October 23 - November 1 Campaign books open for public inspection
October 26 7-day pre-general C-4 report due - report for the period Oct 12 through Oct 25
November 1 Last Monday that weekly C-3 reports must be filed
NOVEMBER 2 GENERAL ELECTION DAY
December 10 Post-general C-4 due that covers Oct. 26 through Nov 30.  File C-3s that have not been filed for any deposits made in November.
January 10, 2022 End of election cycle C-4 due that covers Dec. 1 through Dec. 31.  File C-3s for any deposits made in December.