Here is a list of school and library closings and curtailed, emergency operating hours for major shopping centers - announced yesterday at the close of business - because of the natural gas shortage and conservation efforts. Many smaller businesses and retail firms plan to operate at reduced hours. Persons should call individual firms for information. Other changes may be announced later this week. SCHOOLS AND LIBRARIES

District of Columbia - St. Martin's school is closed all week.

Alexandria - Three schools will be closed all week. Today, students from Barrett will report to Jefferson-Houston Elementary School and students from MacArthur will go to Robert E. Lee Elementary School. Most students from the occupational center will go to T. C. Williams High School.

Students who normally walk to Barrett should report there at regular hours for bus rides to Jefferson-Houston. Barrett school bus riders should be at their regular bus stops one hour and 15 minutes later than usual. Students who walk to MacArthur should report to MacArthur for bus rides to Robert E. Lee. MacArthur bus riders should be at their regular stops 15 minutes later than usual. Occupational Center students should ride the regular T. C. Williams buses.

The Division of Motor Vehicles has closed its offices in Alexandria and Fairfax.

Arlington - All public schools will be closed through Friday. Various adult classes also are canceled.Athletic contests will be rescheduled.

Fairfax County - Four schools will be closed through Friday: Robinson Secondary, Belle View, Forest Edge and John C. Wood Elementary.

Starting today students at Forest Edge Elementary in Reston should report at noon to be transferred to Hunters Woods School, Reston, from 1 p.m. to 5 p.m. Regular Hunters Woods students will attend school from 8:40 a.m. to 12:40 p.m. Students at John C. Wood Elementary in Fairfax should report at the normal time to be shifted to two schools. Kindergarten and first grade students will go to Layton Elementary across the street; the rest will go to Fairfax High School. Students at Robinson Secondard should report at noon to be transported to Woodson High School from 12:30 p.m. to 4:30 p.m., with Woodson students attending in the morning. Robinson Intermediate students should report at 1 p.m. to be transported to Frost Intermediate from 1 p.m. to 5 p.m., with Frost students attending in the morning. Bellview Elementary's students will be transported to two schools, and should report at the regular time. Kindergarten through third grade students will go to Quander Elementary and fourth through sixth grades will go to Cameron Elementary. The students in the gifted program will go to Cameron and the preschool special education will go to Bucknell Elementary.

All students who are bused will be picked up at their regular stops and transported to their home schools. Further transportation will be provided for all students to their temporary school locations.

Four libraries will be closed through Saturday; the Central Library in Fairfax City, Richard Byrd Library in Springfield, the Thomas Jefferson Library outside Falls Church, and the Kings Park Library in Burke. For information on the hours of other libraries call 691-3187.

Voter registration will be held from 7 p.m. to 8 p.m. Thursday at the following libraries: Centerville, Dolley Madison, John Marshall, Martha Washington, Patrick Henry, Tysons-Pimmit and Woodrow Wilson.

Falls Church - All four public schools will be closed all week. The Falls Church Public Library will be open today through Friday from 9 a.m. to 9 p.m. and Saturday from 10 a.m. to 2 p.m.

Prince William County - The following elementary schools will be clossed today: Westgate, Featherstone, Carrydale, Marumsco Hills, Potomac View, Elizabeth Vaughn and Rockledge. The School Board will announce a schedule on Thursday for the remainder of the week.

Prince George's County - Most schools will operate on a normal schedule this week. The three special education centers will reopen this morning on 2 normal schedule. They are H. Windship Wheatley, Princess Garden Special Center and Annex and Hillcrest Heights. The following schools will reopen today through Friday, two hours later than normal: Steven Decatur Junior High, Robert Frost, Samuel Morse, Paint Branch, Seat Pleasant, Patuxent, Pointer Ridge, William Beanes, Camp Springs, Francis T. Evans, Adelphi, Longfield, James Harrison, Doswell E. Brooks and all morning and afternoon kindgergarten classes will attend a full day. Students should plan to buy lunches. Schools now are allowed to set their thermostats at 65. There is no change in normal dismissal time.

Montgomery County - Fifteen gas-heated public elementary schools will be closed today through Friday. They are: Chevy Chase, Forest Grove, Hungerford, Montgomery Knolls, Piney Branch, Pleasant View, Tuckerman, Rock Creek Forest, Somerset, South Lake, Strathmore, Summit Hall, Takoma Park, Wheaton Woods and Whittier Woods. However, students should report to their schools for temporary reassignment starting today. Those who ride school buses will be picked up at the normal time and place. Students who normally walk to school should walk and on arrival at their schools they will be bused to a nearby school. Those students who walk to school will be returned by bus to their neighborhood schools at 2 p.m. Students who normally are bused to school will be bused home at the close of the regular school day. All school buildings are available for evening meetings for community groups at the normal fee.

The two senior citizen recreation centers will be closed through Friday.

Public libraries will be open from noon to 8 p.m. through Friday. STORES AND SHOPPING CENTERS

Giant - In Virginia, most will be closed Sundays and open from 2 p.m. to 8 p.m., Monday through Thursdays, from noon to 8 p.m., Fridays, and 10 a.m. to 6 p.m., Saturdays.

Safeway - In Virginia, most will be closed Sundays and open from 2 p.m. to 8 p.m. Tuesdays through Thursdays, and from noon to 8 p.m., Fridays and Saturdays.

Grand Union - In Virginia only most will be closed Sundays and open from noon to 6 p.m., Mondays 1 p.m. to 6 p.m., Tuesdays and Wednesdays, noon to 8 p.m., Thursdays and Fridays, and 10 a.m. to 6 p.m., Saturdays.

A&P - In the District of Columbia and most of Maryland they will be open from 9 a.m. to p.m., Mondays through Fridays and Sunday hours remain the same.

ABC Stores - Will be open from 11:30 a.m. to 6 p.m., Mondays through Saturdays.

Dart Drug - In Virginia, they will be open from 1 p.m. to 6 p.m., Mondays through Fridays, 10 a.m. to 5:30 p.m., Saturdays and Sundays except for 1735 N. Lynn St., Arlington, which will be open from 11 a.m. to 6 p.m., Mondays through Fridays and noon to 5 p.m., closed Sunday, 7271 Arlington Blvd., Falls Church, will be open from 1 p.m. to 6 p.m., Mondays through Fridays, and 6 p.m. to 1 p.m., Mondays through Fridays for prescriptions only.

People's Drugh Stores - In Virginia, noon to 8 p.m., Fridays, 10 a.m. to 6 p.m., Saturdays, and noon to 6 p.m., Sundays. At the discretion of store managers in certain districts where there is more than one People's, one will close on Tuesday or Wednesday.

Drug Fair - In Virginia, times have been posted in the stores and vary from store to store.

Springfield Mall and Tysons Corner Shopping Center - They will be open from noon to 5 p.m. Sundays, 2 p.m. to 8 p.m. Mondays and Wednesdays, 2 p.m. to 9 p.m. Thursdays and Fridays, and from 11 a.m. to 8 p.m. Saturdays.

Landmark Shopping Center - Most of its stores will be open from noon to 5 p.m. Sundays, 2 p.m. to 8 p.m. Mondays and Wednesdays, 2 p.m. to 7 p.m. Tuesdays, 2 p.m. to 9 p.m. Thursdays and Fridays, and 11 a.m. to 8 p.m. Saturdays.

Seven Corners Shopping Center - Most of its stores will be closed Sundays and open from 2 p.m. to 8 p.m. Mondays and Wednesdays, 2 p.m. to 7 p.m. Tuesdays, 2 p.m. to 9 p.m. Thursdays and Fridays, and 11 a.m. to 8 p.m. Saturdays.

Lord & Taylor store at Seven Corners: It will be open today, and Fridays from 11 a.m. to 5 p.m. On Thursday it will open from 11 a.m. to 8 p.m. and on Saturday from 10:30 a.m. to 5:30 p.m.