I'm not sure if you are inquiring about the time of day or what month so I'll tell you both. Generally the best months to visit are May to October for mild weather. The best time of day would be before the sun comes up or after 3 p. m.
The best time is April or May, after Peru's rainy season and before the crowds of tourists in the summer. February and March are also sometimes good - warm days and cold nights, though.
