Yes, tonight is the night to set the clocks back.
More specifically, daylight saving time ends Sunday, Nov. 3 at 2 a.m. The time shift will result in less daylight, meaning that many of us will be waking up in the dark and heading home from work in the dark.
Daylight saving time became official with something called "war time," when President Franklin Roosevelt codified the time shift to save resources. War time was enforced 40 days after the bombing of Pearl Harbor, and some time zones were even called Pacific War Time or Mountain War Time. (Many still dispute whether daylight saving time really triggers significant economic savings.) After the war, saving time remained but a number of states opted out until the Uniform Time Act of 1966 was passed. Yes, it's mandatory but Arizona and Hawaii still choose not to "spring forward" for daylight saving time.
Standard time, which we're about to enter Sunday morning, is what many people consider to be "more normal" as it has been around since the 1840s. Standardized time was primarily instituted to help manage railways; in fact, it was known as "railway" time for decades. But standard time was not enacted into U.S. law until the 1918 Standard Time Act.