The Wikipedia has the information I needed: "St. Giragos is an Armenian Orthodox Church in Diyarbakır, which although out of use has recently been renovated in part as a sign of reconciliation with the Christian community. It was reopened on 23 October 2011 as "Turkey’s first church to be revived as a permanent place of worship" and also houses an Armenian museum - the first of its kind in Anatolia.

It was seen as one of the largest and most important Armenian churches in the Middle East, with seven altars. It was closed during the Armenian Genocide in 1915-1916, and was returned to the local Armenian community in 1960, although due to emigration in the 1970s and 1980s the local Armenian community was much diminished. According to some art historians, the church is the largest in the Middle East. The complex sprawls over 3,200 square meters and includes priests’ houses, chapels and a school. The church was seized by the German army in 1913 and served as their local headquarters until 1918, when it was converted into a fabric warehouse. Ayık [I guess part of the information came from some interview that mentioned who this spokesperson was D.O.] also said St. Giragos had several unique architectural features. "Churches normally have one altar but St. Giragos has seven altars. Its original roof was covered with the earth from around the region. We will do it again. The earth has been stripped of seeds to prevent the growth of plants. It should also be vented regularly, every year." The chairman, whose family is originally from the southeastern province, said the church was handed over to the foundation by the General Directorate of Foundations in the 1950s and continued providing church services until 1980. After the founding of the Turkish Republic in 1923, it was used as a state warehouse for canvas and fabrics, and then, despite sporadic efforts by the dwindling Armenian community in Diyarbakır, it had been left to deteriorate and decay until 2009, when a few Armenians born in Diyarbakır but living in Istanbul, formed a Foundation Board under the auspices of the Armenian Istanbul Patriarchate, with the goal of reconstructing the church, as well as to start a legal process to reclaim title to the significant land holdings originally belonging to the church."

If I understood correctly there are about three services a year, but that may grow. The church has been awarded a Prize for Cultural Heritage of the EU in 2015.