Last-minute tax filers are likely to have one more item on their checklist – how to secure a coveted April 18th Postmark. All area Post Office retail windows will maintain regular customer service hours on Tax Day, April 18th. No Northern Nevada offices will be staying open late. However, for those who need a last minute postmark, the Reno Main Post Office at 2000 Vassar Street will accept tax returns for postmarking up to 12 midnight on April 18th. There will be no retail services, but the drive-up collection boxes outside the office will be available for properly stamped envelopes. A self-service stamp kiosk is available in the lobby 24 hours a day.