How to Circa Date Persian Rugs

Use a lunar calendar to date a Persian rug woven during the 17th through the 19th centuries. Rugs of this time period often included a date from the lunar calendar woven into the design. To approximate the date, add 622, then subtract the sum of the lunar date divided by 33.7. For example, if a Persian rug contains the lunar date 1250, the calculation would be: 1250 plus 622 minus 37 (1250 divided by 33.7), making the circa date 1835.

Use the solar calendar to date a Persian rug woven after 1900. To find the date of these rugs, simply add 622 to the date imprinted on the rug. For instance a solar-dated Persian rug bearing the year 1350 would have been made circa 1972.

Take the Persian rug to an antiquities or Oriental rug dealer or appraiser if you cannot determine the dates using either of these methods. Professional dealers or Oriental rug purveyors may be able to assist in determining the circa date.