Calculate Percent of a Year

Calculator, how many percent of a year at a given date have already passed and how many percent are still ahead. Enter time and date and select, if it is a leap year or not. Current time and date and leap year are preselected. The percentage values for this date are calculated when the page loads, i.e. how many percent of the year has already passed and how large the portion is that is still to come.

Example: on September 1st at noon, about two thirds of the year have passed, or more precisely, in a normal year it is 66.712 percent and 33.288 percent are still standing. In a leap year, however, it is 66.803 and 33.197 percent. So the difference is not very big. The reason for this difference is of course February 29th, which only occurs in a leap year and which is in the first half of the year. In a normal year, the exact half of the year is on July 2nd at 12:00 noon, but in a leap year the date is midnight between July 1st and 2nd.

Expressing the part of a year in percent is rather unusual, but it can be helpful to clarify time periods, to estimate them better and to be able to compare them easily. In addition, the information is exact, unlike the length in months.

To find a percentage of the year that does not begin on January 1st and end on December 31st, you can simply calculate the percentage from January 1st to the end date minus the percentage from January 1st to the start date. For example, the percentage from August 11th to November 22nd in a year, each at 12:00 noon, is 89.178 percent minus 60.959 percent, which is 28.219 percent.