Rasamanjari 6.242

6.242

vyabhre varṣāsu vidyāttu grīṣmakāle tu śītale /
hemantakāle madhyāhne śastrakālāstrayaḥ smṛtāḥ //

One should know [the time for bloodletting] to be when the sky is free of clouds during the rains, in the cool time during the summer,
and at midday during the winter: these three are taught as the times for using the blade.