Last-Minute Tax Filers Enjoying Weekend Reprieve : Deadline: But the April 17 filing date has given some a false sense of available time, CPAs say.

It comes once every seven years, and taxpayers love it.

Tax Day, April 15, falls on a Saturday this year, bumping the deadline for returns to the following business day, Monday, April 17.

Robert Bope, like other 11th-hour payers, is taking advantage of the delayed deadline. He leisurely strolled into the Santa Ana post office Friday morning to pick up his tax forms and said, “Sure, it’s nice to have the weekend to do it. I’ll probably do it Saturday morning or something.”

While the extra two days give taxpayers some breathing room, it is driving accountants and postal workers zany. Deluged with calls and clients these past weeks, Robert Dudley, a Mission Viejo accountant, suspects the extended deadline has allowed taxpayers to become worse procrastinators.

“It’s been extremely hectic this year,” Dudley said. “I’ve been putting in about 70 hours a week.” And he expects to pull another 25 hours this weekend. “At least it will be the last of the worst workweek of the season,” he said.

The same has been true for G. Brad Fries, a tax adviser in Lake Forest. Some workdays have lasted from 5 a.m. to 11 p.m., he said.

Last Saturday, dozens of clients were streaming into his office, asking him to work miracles and prepare their tax forms by Monday.

“The more complicated returns, usually young entrepreneurs, practically wait until the 12th hour,” Fries said. “I’m going to hit the golf course Tuesday.”

As time is ticking, Fries offered taxpayers some last-minute tips:

* Do not write “IRS” on checks. Spell out “Internal Revenue Service,” because it is easy for someone to change IRS to MRS .

* If you are filing for an extension, you still must mail a check by Monday for the estimated amount of tax owed. Checks accompanying 4868 vouchers for extensions should be mailed directly to the Internal Revenue Service.

* State tax returns also are due Monday.

* Divorced parents should not each list the same child as a dependent.

* IRS agents warn that they are increasing the number of auditors to almost 300 by October to examine Schedule C returns, those filed by taxpayers grossing more than $100,000. The IRS also will have access to bank and DMV records to check incomes and receipts.

* Common mistakes involve math. Make sure total wages on W-2 forms equal the amount indicated on the wage line.

* List the name on your Social Security card on your tax forms. Women who drop their maiden names after marriage tend to file under their new names. This can delay refunds by up to 12 weeks.

Postal workers said their extra workload actually began last Monday, the deadline for property tax payments. With long lines, crowded lobbies and people squeezing past the doors just before closing, the scene resembled Christmas season, postal workers said.

“It was like a zoo in here,” postal employee Sophie Moradien said.

The Postal Service urges customers to avoid the crowds by mailing their tax returns before the deadline. They also remind taxpayers to make sure that sufficient postage is affixed.

Gearing up for the last-minute mob, a dozen Orange County post offices are extending their service hours Monday. These offices will offer full window services until 10 p.m. Monday. Mail will be collected and postmarked until midnight at these locations. Their 8:30 a.m. to 2 p.m. Saturday schedule will operate as usual.

At the Santa Ana post office on Sunflower Avenue and Susan Street, Susan will be made one-way only after 4 p.m. for traffic entering from Sunflower.

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

Happy Returns? A dozen post offices in Orange County will offer extended hours Monday to make it easier for taxpayers to meet their obligations on time. Normally, the tax deadline is April 15. Because that date falls on a weekend, the Internal Revenue Service has extended the deadline to Monday. Post offices will retain their normal schedules on Saturday. The following post offices will remain open to postmark tax returns until midnight and will offer services, including weighing, certification and stamp sales, until 10 p.m.: Anaheim: 701 N. Loara St. Costa Mesa: 1590 Adams Ave. Huntington Beach: 6771 Warner Ave. Irvine: 15642 Sand Canyon Road / 17192 Murphy Ave. Laguna Niguel: 29911 Niguel Road. Mission Viejo: 28081 Marguerite Parkway. Newport Beach: 1133 Camelback St. Orange: 1075 N. Tustin St. Placentia: 1400 N. Kraemer Blvd. Santa Ana: 2201 N. Grand Ave. / 3101 W. Sunflower Ave.