This article is from the Meditation FAQ, by Jeffrey Chance jeffjc@cs.mcgill.ca with numerous contributions by others.
When first learning meditation it is usually not possible
to meditate for more than 10-15 minutes. After regular
practice for awhile, one becomes able to meditate for
longer periods of time. Many people meditate twice-daily
for 20-30 minutes each time, but the right duration and
frequency is for each individual to decide.
 
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