In the United States, tomorrow is the National Day of Prayer,* held on the first Thursday in May.** Most people I know consider this a day of Christian prayer. But as a national day it is designated by Congress for each American to pray according to his or her own beliefs. Many of the more prominent events are Christian events, planned by private rather than governmental entities. For example, the National Day of Prayer Task Force is a privately funded Christian organization.
I suppose at best I have little feeling toward the day (either for or against). The day has never been a part of my tradition and background, and additionally I'm not much of a celebrater of days (even though I often acknowledge them on my blog). If truly celebrated nationally the National Day of Prayer would be quite an ecumenical event -- not just all denominations of Christians, but Jews, Muslims, and all religions (or non-religions) who hold prayer as part of their tradition. But, on the other hand, it is nice to live in a country that officially recognizes that prayer is an important part of the lives of its people.
"Pray without ceasing." -- 1 Thess. 5:17
* The National Day of Prayer was created in 1952 by a joint resolution of Congress.
** When I looked for this NDOP on my calendar, I did not find it but found "Ascension Day". Being a backward Baptist, I had to look it up. It marks the "church calendar" date to celebrate the ascension of Jesus, approximately 40 days after Easter Sunday.