Time and Frequency of Meditation
Some puthujjanas manage to think that they will progress by spending 20 minutes per day watching the thoughts and suppressing thoughts of harm and lust, then  spending the rest of the day allowing bad thoughts permeated with sensuality, ill-will and harmfulness.  

Of course, the only progress possible is first to be mindful of thoughts and perceptions all the time, in order to keep only the good ones.

Sila is made complete with sati sampajana. When sati sampajana declines, sila declines. Without  mindfulness, a puthujjana will only a have sila for a few minutes up to a few hours