In 1863, president abraham lincoln designated the last thursday in november as a national day of , in 1939, president franklin roosevelt decreed that the holiday should always be celebrated on the fourth thursday of the month.

Finally, in 1939, President Franklin Roosevelt decreed that the holiday should always be celebrated on the fourth Thursday of the month.

Explanation:

In the year 1939, President Franklin D. Roosevelt has moved the Thanksgiving holiday by one week before than regular schedule, thinking that by rescheduling the holiday it would help increase the retail sales during one of the final years of the Great Depression.

He felt that last Thursday in November fell on the last day of the month which would make no time for Christmas shopping season and it might diminish the economic revival.

So, President Franklin D. Roosevelt issued a Presidential Proclamation moving Thanksgiving to the second to last Thursday of November which has led to much confusion and disapproval, causing some to ridicule the holiday as Franksgiving.