You could write a 50,000 word novel in 30 days if you write 1,667 words every day. You could also write it in 90 days, just 3 months, if you write 555 words every day. Or you could write it in 6 months with a scant 277 words each day.
The average person can write about 25-40 WPM (words per minute). Assuming 25 WPM, it would take just over an hour (66 minutes) to write 1,667 words, about 20 minutes to write 555 words, or just over 10 minutes to write 277 words. There are 10 spare minutes in each of your days. That will suffice if you stick with it long enough.
However short or long of a time you take to write each day, you want to make the most of it. Plan ahead: find quiet (or relaxing noise), have your computer or legal pad at the ready (including the pen), have your beat sheet on hand and your imagination poised. With preparation and persistence, you can write a novel this year.