Beginner of chanting

Hello,
i am sure everyone here already is some kind of profesional in doing yogas and knows also some details of doing mantras.
I am a bit confused, my vedic astrologer adviced me do some extra mantras for weak planet positions in horoscope … i learned some specific number should be done in right number of days? I wanted to ask, can i do mantra for sun on days of its enemy? Should i make break and do more mantras on right day or this 40 day number can last also longer time just main idea it should be compleated in these 40 days …

Thanku very much, waiting your opinions … :oops:

Mantras are transient tools of symbolism.
Their only power is suggestive in nature.