In the USA, the 4th of July is a federal holiday. Though fireworks and 4th of July activities are usually celebrated on the actual date - if the 4th of July falls on a Sunday, the federal observed holiday is the following Monday. If July 4 falls on a Saturday, for most Federal employees (but not all), Friday, July 3, will be treated as a holiday for pay and leave purposes.
There will not be car seat inspections on July 4th.