(1) A period of strict rule, marked by dicipline and punishment following a period of lax rule, marked by lax enforcement of laws and standards. The opposite of Dinkins Time.
(2) The point at which an individual is not going to take any more crap.
Rudolph Guiliani, mayor of the City of New York from 1994 to 2001, engineered a decline in crime, which had spiked sharply during the tenure of David Dinkins. His success was largely the product of strict enforcement of minor laws, following the broken window theory of law enforcement. Police were empowered to take control of neighborhoods, and not let minor crimes go unpunished, lest tolerance of small crimes lead to the enabling and tolerance of larger crimes.
The downside to this decline in crime was a police force that was often criticized for being overly aggressive and occasionally brutal. One victim of police brutality during Guliani's rule was Abner Louima, a Haitian immigrant arrested outside a nightclub. While handcuffed, Louima was sodomized with a wooden stick in a bathroom at the 70th precinct in Brooklyn.
Several officers were convicted of various offenses related to the violation of Louima's cornhole, and are currently serving terms of up to thirty years. However, the officers were nearly acquitted when Louima was found to have fabricated part of his story, initially alleging that the officers told him that "it's Guiliani Time, not Dinkins Time," then recanting. The idea to allege that the officers made such a statement was likely planted in Louima's head by black activists of the Al Sharpton/Jesse Jackson type who saw this crime as an opportunity to score political points against a mayor who didn't kowtow to the demands of the racial grievance industry.
In the 2000 film "Shaft" (a remake of the 1971 blaxploitation classic), John Shaft (Samuel L. Jackson), a retired NYPD officer, uses the phrase "it's Guiliani time" after beating the crap out of a thug. Since then, it has blossomed into an all-purpose bad-ass remark.
*Smacks girlfriend for staying out too late with her fugly chickenhead friends*
Woman: "You never had a problem with me staying out until whenever with my girlfriends before!"
Me: "Bitch, it's Guiliani Time!"