Now that the government shutdown is over and the United States government has reopened—at least for now—many people are wondering how to approach the 2019 tax season, which officially opened on Jan. 28. As of Monday, the Internal Revenue Service is accepting tax returns. If you were one of the prepared people hoping the government would reopen in time for tax season, you can go ahead and file—if you didn’t already.

That said, it’s hard to know what to expect this year due to the Tax Cuts and Jobs Act, passed by Congress in 2017. The new laws could cause this tax season could be particularly unusual, as the new tax code introduces more sweeping changes than we’ve seen in over 30 years.

For those that file returns early, the IRS says to expect the first refunds to go out in the first week of February. Many more refunds will be paid by mid- to late-February, as has been true in previous years. On IRS.gov, taxpayers can refer to the “Where’s My Refund?” section, where information on your most recently filed return is generally available 24 hours after filing online. Information on paper returns filed by mail is generally posted within four weeks of mailing.

Tax returns for 2019 must be filed by Monday, April 15 unless you file for an extension, or if you live in Maine or Massachusetts. April 15 is Patriots’ Day in those states, and Maine and Massachusetts residents have until Wednesday, April 17 to file.