You could create a language override for the Persian language. The Joomla documentation shows you how to do that: https://docs.joomla.org/J3.x:Language_Overrides_in_Joomla
You could copy the following English language strings from /language/en-GB/en-GB.ini to your Persian language override:
DATE_FORMAT_LC="l, d F Y"
DATE_FORMAT_LC1="l, d F Y"