- 28December 28, 1919No events
- 29December 29, 1919No events
- 30December 30, 1919No events
- 31December 31, 1919No events
- 01January 1, 1920No events
- 02January 2, 1920No events
- 03January 3, 1920No events
A=ANNUAL
M=MONTHLY
Q=QUARTERLY
DISCLAIMER: THESE DUE DATES ARE SUBJECT TO CHANGE. WE WILL DO OUR BEST TO KEEP THIS CALENDAR UP TO DATE WITH THE EVERCHANGING DEADLINES. ANY STATE FILING DUE DATES ARE IN REFERENCE SPECIFICALLY TO THE WASHINGTON STATE DEPARTMENT OF REVENUE.