You’re always going to wish you had another hour or another day or another week to finish up a project. There’s never enough time to make your project perfect because it will never be perfect.
As a creator the flaws of your project will always appear to be magnified 100X, covered in flashing Las Vegas-style marquee lighting, with a giant red arrows pointing out every single defect.
And although I know you won’t believe me — no one else is seeing the project the way you are. No one noticed the subtle color variation in your background, that you the last paragraph was set in Arial instead of Helvetica, or that the image on page 3 isn’t in the exact center of the page.
You’ll never have enough time to complete all your tweaks and adjustments
If you asked for an extra hour and you were told to take an extra day, you’d still wish you had another week to work on the project.
Take the time you’ve been allotted, schedule your development assignments accordingly, and when the deadline whistle blows put down your tools and step away from your workbench.
If you’ve done the best you can with the time you were allowed, you should be proud of the work you’ve done and the effort you invested.
You can always think about the improvements you’ll make in version 2.0.