Crow hunting is limited by federal regs to X number of days a year. I am not sure of the total number, but TN has chosen to use their allotted days by having crow hunting open Friday-Sunday from June 1-Feb. 28.
The limit on the number of crow hunting days is a result of a treaty with Mexico. The US wanted increased protection for wintering waterfowl in Mexico. Mexico wanted increased protection for ravens. Due to their close appearance to a crow, there was a federal reduction in the number of days of crow hunting in the US as part of the treaty agreement.