Putting off looking for a job until after the holidays? That could be a mistake, says a national outplacement firm.

Long perceived as a poor time to go job hunting, the Christmas holiday period always offers opportunities, but its more competitive this year because of recent gains in equality that older workers now enjoy in the job market.Surveys show a virtual tie in job search time among discharged people under and over age 50, said James E. Challenger, president of consulting firm Challenger, Gray & Christmas, Inc. The company's 15 offices nationally offer outplacement services to corporations who choose to help personnel they have terminated, for whatever reason, to find a new job.

Challenger said those age 50 and over currently require 3.23 months to find new jobs compared with 3.0 months for job seekers of all ages, a difference of only seven more days. The norm is 3.2 months.

"This is a reflection of the change in corporate hiring attitudes toward acceptance of older, more experienced workers which began early in 1985 and has shown no signs of discontinuing," said Challenger, whose company was the first to offer outplacement to corporations.

Challenger says enterprising job seekers this holiday season will capitalize on the job market by:

Lining up interviews now. The weeks during the holidays present excellent opportunities for arranging interviews because potential employers, with the exception of retailers, are likely to have more time while normal business activity is slack, said Challenger. Many companies are planning 1989 budgets and determining positions to be filled.

Listing their accomplishments. Getting a job requires the ability to "brag successfully," he said. "You do this by emphasizing your performance, citing specific examples of what you have accomplished on past jobs."

Positioning themselves as problem solvers. Employers, said Challenger, are looking for people who can make an immediate contribution to the bottom line by suggesting ways to improve the company's profitability.

Broadening their job search base. Moving is now widely accepted by both employers and employees as a way to a better job, he said. Currently, 34 percent of job seekers are moving to accept a new job, up from 25 percent only five years ago.

Turning a discharge into a plus. Companies looking to hire no longer regard discharge as a negative, said Challenger. The aggressive job seeker should take the position that the discharge is a benefit that has opened up new career opportunities.

Not lowering their salary requirement. Higher-paid managers do not have to settle for less than their salary requirement, Challenger claims, because the marketplace and the overall economy appear to be on their side, at least on a national basis. Also, good jobs continue to be available in the middle income as well as the higher income ranges.