A Lawrence tradition celebrating the last-minute mailing of income taxes at the downtown post office will continue this year, but things will be different.

“It’s going to change significantly,” said Steve Mason, one of the members of the Alferd Packer Memorial String Band, which on Monday night will mark its 19th year of performing at the tax night party.

The obvious difference this year is that tax night will be April 17, because the traditional April 15 tax deadline is on a Saturday.

And unlike past years when the Lawrence post office at 645 Vt. stayed open until midnight postmarking and collecting envelopes headed for the Internal Revenue Service, this year it will close at 7 p.m.

The early closing is necessary because during the past two years the U.S. Postal Service has cut back on working hours on tax nights across the nation, Lawrence Postmaster Judy Raney said.

“We kind of got a special exemption last year,” Raney said.

Last year’s tax party was taped by a TV news crew preparing a segment on the event for “CBS Sunday Morning.” Correspondent Bill Geist reported on the event.

Matt Kirby of the Alferd Packer Memorial String Band dances to the delight of taxpayers last year at the post office, 645 Vt. The band's traditional midnight rendition of the William

But while the post office will close earlier than past years’ tax nights, the lobby will stay open and the Packer band will perform.

“They are still more than welcome to be here in the lobby,” Raney said. “We’d be happy to have them.”

So the band noted for its novelty songs and acts will play on.

“Oh, sure, we’re going to do our thing,” band member Matt Kirby said, adding that a change was sort of expected. “We had already talked about doing it anyway.”

The band also is noted for playing the “William Tell Overture” during the last few minutes leading up to the midnight tax deadline. A crowd of onlookers forms a gauntlet from the door to the mail slots for the last-minute filers to run through.

This year the band will start playing early, about 6:45 p.m., Mason said. About four minutes before 7 p.m. it will begin the musical countdown to the deadline, he said.

Details about Monday night’s event were still being worked out because Mason and Kirby said that they had been unable to find out what the post office’s plans were until Tuesday.

“Now that we have confirmation, things will start falling into place,” Mason said, adding that the band probably would play until 9 p.m.

Anyone wanting to get their taxes postmarked and mailed will have to do so before 7 p.m., Raney said. After that, while the lobby will remain open, there will be no retail service and no mail collection by employees.