Giving thanks is a characteristic of being filled (controlled) by the Holy Spirit (Ephesians 5:20).

As a characteristic of being filled by the Holy Spirit, giving thanks is not a once a year thing.

Spirit filled thanksgiving is always being thankful for all things. That takes in a lot of territory.  It is also very convicting.

If we believe that God is sovereign, that He is always in control, then we can be thankful for the bad, as well as the good, if we love God and are the called according to His purpose.

Note:  What is the opposite of being thankful? 

Does this mean that griping or complaining is sin?

“If we confess our sins, He is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.” I John 1:9