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

Within 2 weeks of becoming a candidate Register the campaign (File a C-1)
January 10 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 11 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 11 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 10 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 13-17 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 24 Last day before primary election to change from mini to full reporting without special circumstances
July 16

Candidates appearing on the primary election ballot file a C-4 that covers the period June 1 through July 15.

Candidates not on the primary election ballot file monthly reports in June, July, August, and September.

July 27 - Aug 5 Campaign books open for public inspection
July 30 Candidates appearing on the primary election ballot file a C-4 that covers the period July 17 through July 30
July 30 - Aug 5 Special reports due if candidate receives contributions of $1,000 or more from a single source
AUGUST 6 PRIMARY ELECTION DAY
September 3 Last day before general election to change from mini to full reporting without special circumstances
September 10

Post-primary C-4 due that covers the period July 30 through August 31

Candidates not on the primary election ballot file a report for the month of August

October 15 21-day pre-general C-4 report due - report for the period Sept 1 through Oct 14
October 15 - November 4
  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 political party, a candidate may not receive contributions from a single source exceeding $5,000 in the aggregate.  
October 26 - November 4 Campaign books open for public inspection
October 29 7-day pre-general C-4 report due - report for the period Oct 15 through Oct 28
November 4 Last Monday that weekly C-3 reports must be filed
NOVEMBER 5 GENERAL ELECTION DAY
December 10 Post-general C-4 due that covers Oct. 29 through Nov 30.  File C-3s that have not been filed for any deposits made in November.
January 10, 2020 End of election cycle C-4 due that covers Dec. 1 through Dec. 31.  File C-3s for any deposits made in December.