Can I file on April 17,2018?

[PaulGLO]

Yes you can. You can even e-file after that.  But if your getting a refund, why would you wait to get your money back?

If you are waiting on tax documents or forms to file with you'll have to wait until you have everything you need. TurboTax won't let you file an incomplete return. 

If you owe taxes this year and can't pay, file as soon as you can to avoid late filing penalties and interest.

Use the links in this TurboTax FAQ for more information.

  https://ttlc.intuit.com/replies/3301661

[BobinCT]

Yes but why would you want to?  If you owe money you can file now and pay later. It just prints a payment voucher that you mail with payment by April 17.  Waiting until the last minute to file means a big flurry if anything needs correcting in the initial filing.