When it comes to finding deals on pre-owned vehicles, it turns out that holidays may be both the best of times and the worst of times.

According to a recent study by iSeeCars.com that analyzed more than 40 million used-car sales between 2013 and 2015, Black Friday is the best time to find a deal, with 33.1 percent more than average available. Conversely, the 4th of July is the worst time, with 28 percent fewer deals than average.

A deal in this case is defined as savings of at least 5 percent below market value.

“It's always nice to save money, and when you are buying something as expensive as a car, saving even 5 percent of your purchase, or $952 off the average price of $19,040, can really add up,” said Phong Ly, chief executive officer of iSeeCars.com. 

Other holidays found to be prime times for finding deals were Veterans Day (32.5 percent more than average), Thanksgiving (30.6 percent), Columbus Day (30.5 percent), Martin Luther King Jr. Day (29.4 percent), Christmas Eve (28.7 percent), Christmas (21.4 percent) and New Year’s Eve (21.3 percent).

Holidays found to be not so auspicious were Mother’s Day (27.5 percent fewer deals than average), Easter (22.2 percent) and Good Friday (21.6 percent), with Memorial Day and Father’s Day tied at 18.3 percent.

Dealers tend to make a big push to boost sales in the late fall and early winter, Ly said, while the spring and summer months tend to be when dealers see higher demand, and therefore less of a need to lower their pricing. The five-month stretch from April through August was the worst for finding deals, with 27 percent to 10.2 percent fewer deals than average.

Other key findings from the study:

• The best month to find a deal is November (26.9 percent more than average), while the worst month is April (27 percent fewer).
   
• The first day of the month (8.5 percent more than average) has more deals than the last day (slightly lower than 5.6 percent more).
   
• Shopping Monday through Thursday (1.2 percent more deals than average) is slightly better than shopping on weekends (1.6 percent fewer deals).

Taking all these considerations into account, Ly noted, consumers who are planning on buying a used car later this year could be exceptionally well poised for saving money.

“With over 3 million cars expected to come off-lease this year, the used car inventory will grow, making it ripe for dealers anxious to move the cars off their lots," he said.