two different people having the same date of birth or same day as birthday (mind it, only the date is same, because iso = same, dob = date of birth; year may be different)
like isotopes, which are two different atoms (with different atomic mass number) having the same atomic number.
like Mayank & Paremal having their birthday on the same day, call each other:

Intelligence agency term for "psychological operation". A government or corporate-sponsored operation, usually taking the form of a "terrorist attack" or "crazed gunman on a spree", with the intent of panicking the public into demanding more police and laws inhibiting freedom. Psyops are usually carried out by drugging a civilian or group of civilians with aggression-promoting drugs, psyching them up, arming them, and sending them out to commit mayhem. Government-sponsored terrorism. See also blackshirts, conspiracy