The Hijra-Solar (H.S.) calendar

I show a dual-calendar system on many of my blog posts from Kabul, but the second date is not the Islamic Lunar (After-Hijra) calendar. It is the Hijra Solar calendar, used only in Iran and Afghanistan. This calendar is an Islamic calendar because of its start date (622 AD, the year the Prophet left Mecca to govern Medina), but it is not used for religious purposes. As in the rest of the Islamic world, religious days and months are reckoned by the Lunar Hijra calendar, which precesses through the solar year so that months such as Ramadan come more than a week earlier during each solar year.
The Persian solar year always starts on the spring equinox, and is in fact more accurate than either the Julian or Gregorian Christian calendars (see the Wikipedia article for a detailed explanation). Below I have built a correspondence table of Hijra Solar (H.S.) and Gregorian (A.D.) years, beginning with the year in which Sardar Daoud Khan declared H.S. the official state calendar of Afghanistan.

H.S.

A.D.

H.S.

A.D.

H.S.

A.D.

1/1/
1336

3/21/1957- 3/20/58

1/1/
1354

3/21/1975- 3/20/76

1/1/
1372

3/21/1993- 3/20/94

1337

3/21/1958

1355

3/21/1976

1373

3/21/1994

1338

3/21/1959

1356

3/21/1977

1374

3/21/1995

1339

3/21/1960

1357

3/21/1978

1375

3/20/1996*

1340

3/21/1961

1358

3/21/1979

1376

3/21/1997

1341

3/21/1962

1359

3/21/1980

1377

3/21/1998

1342

3/21/1963

1360

3/21/1981

1378

3/21/1999

1343

3/21/1964

1361

3/21/1982

1379

3/20/2000*

1344

3/21/1965

1362

3/21/1983

1380

3/21/2001

1345

3/21/1966

1363

3/21/1984

1381

3/21/2002

1346

3/21/1967

1364

3/21/1985

1382

3/21/2003

1347

3/21/1968

1365

3/21/1986

1383

3/20/2004*

1348

3/21/1969

1366

3/21/1987

1384

3/21/2005

1349

3/21/1970

1367

3/21/1988

1385

3/21/2006

1350

3/21/1971

1368

3/21/1989

1386

3/21/2007

1351

3/21/1972

1369

3/21/1990

1387

3/20/2008*

1352

3/21/1973

1370

3/21/1991

1388

3/21/2009

1353

3/21/1974

1371

3/21/1992

1389

3/21/2010

*Because of inaccuracy in the Gregorian calendar, the equinox now occurs on March 20 on every fourth year, beginning in 1996. In those years, the H.S. and A.D. calendars are offset by one day. In the table below I give the start date of Afghan months corresponding to AD years in which the spring equinox begins on March 21; but keep in mind that this must be adjusted for every fourth year until the Christian calendar is corrected.

Name Begins Length Name Begins Length
Hamal March 21 31 days Mizān September 23 30 days
Sawr April 21 31 days Aqrab October 23 30 days
Jawzā May 22 31 days Qaws November 22 30 days
Saratān June 22 31 days Jadī December 22 30 days
Asad July 23 31 days Dalv January 21 30 days
Sonbola August 23 31 days Hūt February 20 29/30 d