Dates in Oriental Rugs

Dates are sometimes woven into the end borders or fields of Oriental carpets, usually using Arabic calligraphy (find out about signatures and inscriptions in Oriental rugs). Usually a date in a rug can be taken at face value, but not always. In the past, rugs were often woven by individuals who were functionally illiterate. Someone else would have drawn the date for the weaver to copy, and the person writing the date may have been only semi-literate. In such cases it is common to see Arabic numerals reversed, woven upside down, or so distorted as to make the date difficult to read.
There is also the confusion introduced by some weaving countries switching from a "lunar" calendar to a "solar" calendar in the 1920's. Because the lunar year is shorter than the solar year, a conversion factor needs to be applied to convert an Islamic lunar calendar date to the corresponding Georgian date.
Finally, there is the problem of a weaver perhaps copying a date from an older rug, or even intentionally "pre-dating" a rug in order to create an instant semi-antique. It is also possible to reweave a small part of the rug to add a date, or to reweave a numeral or two of an existing date to add years or decades to the seeming age of the rug.
So--it's fun to look for (and find!) a date in a rug, but don't bet the farm on the accuracy of that date!

Islamic Dates in OLDER Carpets

Rugs woven and dated in the 17th, 18th, and 19th Centuries almost always use the Islamic lunar calendar. To convert an Islamic lunar date into the Christian or Georgian date, use this formula:

Islamic lunar date + 622 - (Islamic lunar date/33.7) = Christian date

Thus, a woven rug date of "1280" converts like this: Islamic lunar date of 1280 plus 622 minus 38 (38 being 1280 divided by 33.7) = Christian date of 1864

Islamic Dates in NEWER Carpets

By the 1920's, the governments of both Turkey and "Persia" (which changed its name to Iran at this time) converted to a solar calendar, so that the lengths of their months would match the lengths of months in the West (note that the Caucasus, under Russian control since the early 1800's, tended to use the solar calendar earlier than Turkey or Iran). Year One was still reckoned from the Hegira, Muhammad's flight from Mecca to Medina in 622AD. To convert an Islamic solar date into the Christian or Georgian date, use this formula:

Islamic solar date + 622 = Christian date [no lunar conversion factor is needed]
(Note that this conversion is not completely accurate, as the Islamic
and Christian new years occur at different times.)

Thus, a woven rug date of "1376" converts like this: Islamic solar date of 1376 + 622 = Christian date of 1998

Arabic Numerals Used in Dating Rugs

Arabic numerals

Western-style numerals are in red; three versions of numbers in Arabic calligraphy are illustrated below them. Arabic numerals are read left-to-right, as in the West: thousands, hundreds, tens, ones.

OK, enough lecture. Pictured here is part of a Bahktiari rug from Iran with a date woven into the guard border. Pick out the Arabic numbers that make up the date. Now change the Islamic date into western numbers, and convert the Islamic date into the Christian date (HEAVY HINT: this is a new-looking rug; it almost certainly was woven after WWII):

Check your answer.