- 15January 15, 1950No events
- 16January 16, 1950No events
- 17January 17, 1950No events
- 18January 18, 1950No events
- 19January 19, 1950No events
- 20January 20, 1950No events
- 21January 21, 1950No 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.