Sounds like the wages on your paycheck were from 2017. These wages should have been included on the Form W-2 you received from your employer which will be filed for your 2017 tax return. If any of the time worked and paid for was after December 31, 2017, these wages will be included on your 2018 Form W-2. If you are not sure if all of your 2017 wages were included on the Form W-2 (2017), please reach out to your Payroll or HR Department.
Time worked was from 12/17-12/22/2017. But I was paid in Jan 2018. And it was not included on my W-2.
If it was not included on the W-2 you will need to contact your payroll department to correct your W2 or to see if they are going to include it on your 2018 W-2. The IRS is looking for the information reported by your employer. You want to make sure the information you are filing match what the IRS has on file for you.