That's everyone in the US. The self-employed usually pay an estimate of their taxes per quarter, but those who work for companies automatically have their taxes withheld from their salary. Then, when the tax season starts, we have to file whether we owe the IRS more money (not withholding enough tax) or whether we should receive a refund (too much tax withheld) based on the forms we, employers, banks and other companies have received. Investment accounts, etc. And everything is due on April 15, unless you apply for an extension (crashes until October).
It's all very archaic, and the only reason why the US still works like that is that tax software companies like Intuit are actively calling on the government to maintain those complicated tax structures from which they can benefit.
Today, I had to take the PTO off the job to have my change printed and sent in time. But that was my own fault. I could have found out last week if I had taken the time.