About how many years is 1 million days and why?

Answer 1

2,737.8508 years is what you get using 365.25 days.

But on average, a year is 365.241 days. See below. Based on this, 1000000 days is about 2737.918 years.

Here's how I came up with 365.241 days, rather than 365.25, which would be if you added an extra leap day for every 4 years (365 + 365 + 365 + 366)/4 = 365.25 days.

Every century year (years that end in 00 like 1900 & 2100 do not have a leap day, so we subtract 1 day for every 100 years, so a 'normal' century will have 36524 days rather than 36525 days. But every millennium year (years ending in 000 like 2000, 3000, etc) will have the leap day, so 1000 years is 365240 + 1 = 365241 days. Using 365.25, you're only off by less than 0.0025 percent, so for all practical purposes, a year could be considered to have 365.25 days on average. But if you're around in the year 2100, it won't be a leap year.