Christmas Day, Dec 25th, is an annual festival that commemorates the birth of Jesus Christ, widely observed as a significant religious and cultural celebration embraced by billions of people across the globe. It serves as a pivotal feast within the Christian liturgical calendar, following the season of Advent or the Nativity Fast and heralding the commencement of Christmastide, historically a twelve-day festivity culminating on Twelfth Night..

Christmas Day holds the status of a public holiday in numerous countries and is fervently celebrated by the majority of Christians for its religious significance. Moreover, it has evolved into a cultural celebration cherished by many non-Christians, forming an integral part of the broader holiday season that revolves around it.

Thanksgiving Day, Nov 24th, is an annual national holiday in the United States and Canada celebrating the harvest and other blessings of the past year. In the US Thanksgiving is celebrated on the fourth Thursday of November while in Canada nearly one month and a half earlier (second Monday of October). Thanksgiving has deep roots in religious tradition, but nowadays it is primarily celebrated as a secular holiday. 

Thanksgiving tradition began in early XVII century, but the date and popularity varied between states. First nation-wide Thanksgiving was proclaimed on November 26, 1789 by George Washington. The contemporary date of fourth Thursday of November was set in 1941 by federal legislation.