Markandeyapurana 35.41

35.41

śūdrastu māsamāsīta nijakarmavivarjitaḥ /
tataḥ paraṃ nijaṃ karma kuryuḥ sarve yathoditam //

A brahman should spend ten days, exempt from alms-giving, the Homa sacrifice and other pious acts: and a kṣatriya should spend twelve days: and a vaisya half a month; but a śūdra should remain a month, exempt from his peculiar occupation: thereafter all should pursue their own occupation, as already expounded.