Instructions
Look for the date on the Turkish gold coin. If you see a four digit number that looks like a year, it probably is the year. In the 1930s, Turkey began using the Latin alphabet and numbers. Turkish gold coins minted before this time had a Hejira date written in Arabic-Indic numbers. If you don't recognize anything on the Turkish gold coin, move on to Step 2.
Look for Arabic-Indic numbers. These will be four distinct symbols by themselves in a row of four. Most of the other Arabic symbols on a Turkish gold coin will be connected to each other in an elaborate script. The Hejira date on Turkish gold coins is usually on the lower half of the coin reverse.
Compare the Arabic-Indic numbers to a conversion chart (see References). Some of the symbols are similar to Latin symbols. The 1 and the 9 in Arabic-Indic are virtually identical to the 1 and the 9 in Latin. The 4 looks like an E, the 5 looks like a O and the 7 looks like a V.
Note the year written out in Arabic-Indic numbers. This is the Hejira date on the Turkish gold coin. It should be a four digit number starting with a 1. If it is not, you are probably not looking at the date.
Convert the Hejira date to the Julian date. This can be estimated by adding 622 to the Hejira date. However, there are other variables involved. You can find out for sure by using a Hejira to Julian converter (see References).