Federal and D.C. government employees who come to work late because of snow or other weather-related problems may be excused for up to two hours of tardiness without charge to their annual leave.

But the key word is "may." So don't beat the boss over the head if you had troubles this week.

Uncle Sam has five pages of instructions on how to handle wellmeaning stragglers during cold weather. There is another two-page guide for heat emergencies.

Since this is the cold season, it is appropriate to talk about what is in the five-page dismissal and leave treatment guidelines for ice and snow conditions.

There isn't much of a problem if the government decides not to open up (except for key personnel) because of bad weather, or if employees are released early. It either happens or it doesn't.

Figuring time and attendance become a problem only when federal offices open as usual, but because of bad weather, some workers are late or absent. In some instances employees may be excused (without charge to annual leave) for up to two hours by their first line supervisor.

"Tardiness of longer periods," the guidelines advise, "may also be excused without charge to leave in cases which are personally reviewed and authorized by a higher level of management." People who don't made it in at all will usually be charged for annual leave. But, again, there are situations where the supervisor may give those who tried, who desperately wanted to come in but couldn't, the whole day off with pay.

Workers who are off on regularly approved leave may be excused (not charged for leave) for part of the time if their agency doesn't open up, or if it releases employees early. In many cases they can be treated as if they were scheduled for work and excused as other workers.

The guidelines from the Civil Service Commission are not binding on federal agencies, but most follow them. Personnel or administrative offices that want to consult the guides should check FPM Supplement 990-2, Section 610-A-1. They are getting quite a workout these days.

Community Services Administration says its reorganization, which has been in the works for many months, may be delayed from April, the original target date, until May. Workers at CSA are braced for downgradings and possible transfers to the field unless the Carter administration cancels the shakeup.

CSA, the successor to the old Office of Economic Opportunity, has 356 people in headquarters here and another 707 aides in the field. Preliminary spot checks of CSA's grade structure by the Civil Service Commission have shown a substantial number of jobs are overgraded, in CSC's estimation. The agency has asked for a delay in any grade cutbacks, its officials say, until the reorganization is closer at hand.

Meanwhile, CSA is planning a reorganization before the reorganization involving about a score of people in the office of Policy Planning Evaluation. Some workers worry that the post-inauguration changes may be an attempt to give career-job status to the agencies' relatively small group of political appointees. But officials say any changes that take place in PPE will be subject to merit system rules and that those affected by the mini-reorganization will have to compete under civil service procedures.

Virginia M. Armstrong, personnel director of Housing and Urban Development, knew there would be some changes made when she moved down from New York to become one of the government's top-ranking career executives. Among them was her marriage this week to George J. McQuoid, deputy executive director of the Civil Service Commission. In truly modern fashion, she's going to keep her name and McQuoid will retain his.

Government PIO: Agriculture's graduate school has a limited enrollment course ($57) beginning Thursday for people who work -- or want to work -- in federal information offices. The 10-session evening course will be at the Commerce Department Call 447-6337.

Leave Chart: The Washington Post's easy-to-read calendar-style annual leave chart will run in this space Monday. Clip and save it. Reprints will not be available from The Post.

Inauguration Day: Most postal employees in the Washington area will have to work Jan. 20, even though other government workers here will get the day off. The only postal workers who will get the holiday will be those whose offices or regular work sites are within the area of inauguration day activities. Employees outside the downtown area and those in the suburbs will have to work.