This is controlled by anoptional argument called “basis”.
TheYEARFRAC functionreturns the decimal value 0.0388888888888889.
Then this value is formatted with thePercentage number formatwhich displays as a percentage.
The result is the percentage of the year completed through as of today.
This percentage will continually update over time.
For example, 35% is read as “thirty-five percent” and is equivalent to 35/100 or 0.35.
Accordingly, the values in columns C and D aredecimal valueswith thePercentage number formatapplied.