WASHINGTON — The Internal Revenue Service last week announced a program that encourages workers to give up unused vacation time and sick days and turn them into charitable contributions to aid Hurricane Katrina victims.

Employers would convert the donated time into cash contributions to charities while workers would reduce their taxable income by the number of days donated.

A similar program was put into effect after the 9/11 terrorist attacks, but it received only a limited response. Treasury Secretary John Snow and IRS Commissioner Mark Everson said the government plans a greater effort to publicize the new program and expects a better response. Officials refused to provide estimates of lost revenue to the government from the program.

For workers to take advantage, their employers must set up a leave-based donation program under guidelines the IRS will publish. The program will cover unused vacation time, unused sick leave and unused personal leave.

Companies can claim deductions on their tax returns for the amount of money they contribute on behalf of employees who give up leave time, the IRS said.

The IRS also said it was extending some tax deadlines for people living in areas affected by Katrina until Jan. 3. Previously, the IRS had extended these tax deadlines including extending until Oct. 31 the Sept. 15 deadline for individuals to make quarterly estimated tax payments.

The Jan. 3 extension will cover people in Louisiana, Mississippi, Alabama and three counties in Florida.