Optimize code to minimize runtime of the macro

Question

I have been writing some macros to perform some astrological calculations (calculating sign, lunar mansion, D9 & D60). The raw data is in the following format:

Answer 1

Here are some tips that will make a huge difference to your code execution time:

1. Use Option Explicit and declare your variables as the most appropriate date type - only use Variant when you need to.
2. Store your data a numbers (not strings) and use cell format to display as you want
3. Don't loop over (large) ranges. Copy the range data to a variant array, and loop the array. Copy the result back to the sheet at the end. There is lots of examples of this on SO and elsewhere.

To display a number as Deg Minutes Seconds use number format [h]°mm'ss\" This leverages the time format, so you need to create the number value as Deg/24 + Min/1440 + Sec/86400 Eg 293°44'23" has the value 12.2391550925926