The Twinning of Days

It occurred to me on more than one occasion that certain sunsets of the spring resemble those of the fall. On a hunch, I downloaded a chart of sunrise and sunset times for my latitude and imported them into an Excel spreadsheet. I proceeded to analyze.
After taking into account Daylight Savings Time, I found that there were indeed days that had their twins with respect to time of sunset.



4/1/2005
5:50 Sunrise
18:39 Sunset
12:49 Length of daylight

10/7/2005
6:17 Sunrise
17:39*Sunset
11:22 Length of daylight
*Daylight Savings Time: +1 HR

I found it interesting that the twin for my birthday, October 7th is April 1st-- April Fool's Day.