- 27September 27, 1801No events
- 28September 28, 1801No events
- 29September 29, 1801No events
- 30September 30, 1801No events
- 01October 1, 1801No events
- 02October 2, 1801No events
- 03October 3, 1801No 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.