The answer in short, they are lying.
The fastest curing urethane on the market right now is a 1 hour safe drive away time. This gives the windshield enough time to properly cure in place and not leave you or your family in danger in case of a collision or rollover. Too often in the automotive replacement glass industry do we let our busy schedules overshadow life threatening safety concerns. The 1 hour safe drive away time is only if the replacement shop decides to spend the extra money on fast curing urethane. Many shops skimp on these costs and use urethanes that fully cure anywhere from 4-16 hours!
As a consumer, you need to be aware of this and make sure you use a reputable shop and ask the right questions beforehand. Here at American Mobile Glass http://www.autoglassnj.com we use nothing but DOW Express Kits which have a 1 hour drive away time all the way down to 0 degrees Fahrenheit.
Not enough people recognize the importance the windshield plays in the overall structure of the vehicle. This is what holds the entire vehicle together when a rollover happens. This is what the airbag hits against when there is a collision. Why people choose to go with lesser quality glass and urethanes when changing their windshield is beyond me. These decisions have cost people their lives in the past. Don’t make the same mistakes they did. Choose a reputable shop that uses top of the line urethane and glass for the safety of you and your family.