How to replace a string at a particular position

Question

Is there a way to replace a portion of a String at a given position in java script. For instance I want to replace 00 in the hours column with 12 i

Answer 1

A regex approach

"Mar 16, 2010 00:00 AM".replace(/(.{13}).{2}/,"$112")
Mar 16, 2010 12:00 AM