The Week of Prayer for Christian Unity is an international Christian ecumenical observance kept annually between January 18 and 25. It is actually an octave, which means the observance lasts for eight days.
The observance began in 1908 and was focused on prayer for the church unity. The basic idea, and the January dates, were suggested by Father Paul Wattson, co-founder of the Graymoor Franciscan Friars. Watson conceived of the week beginning on the Feast of the the Conversion of St. Paul and concluding on the Feast of the Conversion of St. Peter. The dates and ideas actually were a variant of the Protestant version of these Catholic celebrations. (Wattson was himself a former Anglican priest.) In the mid-1920’s Protestant leaders proposed an annual octave for unity leading up to Pentecost. (Many local communities also celebrate this time and offered joint prayers for unity.) Pope Benedict XVI “encouraged its observance throughout the entire Roman Catholic Church.”
What is interesting is that this observance began in Catholic circles but once it jumped boundaries it took new forms and meanings. Abbé Paul Couturier of Lyons, France, who has been called