This world-wide event is held on Pentecost Sunday every year (19th May, 2013). It began in Capetown, South Africa in 2000. Today it has spread to many countries with an estimated 26 million people praying.
But it is no longer a single event but a season of prayer for the world starting with 10 days of preparation before on Ascension Day (9th May) and continuing for 90 days of blessing afterwards making it a lifestyle of prayer.
Use these resources to help you to pray.
Prayer to use on Pentecost Sunday in various formats found at http://www.globaldayofprayer.com/index.php/gdop/gdop/