How many days in a year?

-I know that there is 365 days a year, but there is a decimal point at the end and I don't know what the decimal is. And I know that we have a leap year every 4 years because of this decimal. Please help me.Do the math, 365.25. .25 every year equals 1 day in four years.
.25 or 1/4. Choos bet answers plz