From WorldChristian.com:

Come join millions of Christians worldwide who since 1993 regularly participate in this largest ongoing international call to Christians to pray for the Muslim world during the annual Ramadan. Ramadan is Islam’s important annual month of fasting and religious observation; in 2019 it starts on May 6.

While we celebrate 26 years in 2019, this marks the 28th time (Muslims use a shorter lunar calendar year) that Christians around the world will join together to intentionally but respectfully learn about and pray for our world’s Muslim neighbors–with faith, hope and love–during their 30 days of Ramadan.