I don't know of a spreadsheet, but it would be nice to calculate the benefit relative to the variable for all the AW's levels at once.
The PT, ETC, and LGN are the 3 Ancient Wonders that increase effect duration.
My Lighthouse of Good Neighborhood (level 12) gives a bonus of 22 h 48m. At level 16 it would be 28h. My total duration is 3d 7h (79 hours). I really don’t know where that comes from.
The PT, ETC, and LGN are the 3 Ancient Wonders that increase effect duration.
If you hover over the hourglass this overview will pop up, but as is typical the information is a bit confusing.
Basic Duration of the Ensorcelled Endowment is 48-hrs.
Ancient Wonder Power is +82.5% of the Basic 48-hrs duration.
Increased Duration is the sum of the Basic Duration of 48-hrs + (.825*48), which is 87-hrs and 36-minutes.
Hope that helps