- 19December 19, 1999No events
- 20December 20, 1999No events
- 21December 21, 1999No events
- 22December 22, 1999No events
- 23December 23, 1999No events
- 24December 24, 1999No events
- 25December 25, 1999No 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.