In Shiva Sahasranāmstrotram, one of names of Shiva is Samvatsarakara.
Why is he called so? Is/Was there a calendar associated with Lord Shiva?
The sloka 57 of the Shiva-Sahasra-nAma reads
samvatasaras tvam ritabo maso mAsardham eva cha--meaning [Lord Shiva!You are] the year, the seasons, the month, and the halves of the months .
The sloka 81 reads
chandrAvarto yugAvartah samvartah sampravartakah---meaning [You are] the Mover of the Moon along its orbit, the month and the initiator and changer of the yugas.
'Samvatsarakara' is NOT there according to the text available to me.However, they connote the same meaning.
The Lord is everything and He is the Doer of everything. He is KAla (the Time) Himself and naturally He is the maker of the year, the year and all parts of the year Himself. So ALL calenders are associated with Lord Shiva.
In Vishu-SahasranAma also we get
'ahah samvatsaro varshah' etc as the names of Lord Vishnu. So the basic connotation is the same and both are parts of the Mahabharata.