Calculating the time of Twilight and Sunrise / Sunset

Looking into the ‘Daily Pages’ of the Nautical Almanac, you will note on the right hand side, the times of Nautical, Civil twilight as well as Sunrise and Sunset (Sunrise at the top of the page, Sunset at the bottom of the page). Times are given for a variety of Latitudes (North and South).

The daily pages give 3 consecutive dates, but the times for twilight etc. are for the ‘central’ day. If you are using the middle day, you can simply pull the times from the table, but if you are using either the day at the top or the bottom of the page, you will need to interpolate between the 2 central days.

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