Converting date to fractional date for BEAST phylogenetic analysis software

While running BEAST, we need to generate an xml with the parameters. When we import the alignment file into BEAUti software and we require the sampling time in fractional years. Here is one way to do that in the excel. Regardless of your date is in any of the formats, the formula would convert that into a fractional year.


=YEAR(A1)+((A1)-DATE(YEAR(A1),1,0))/(DATE(YEAR(A1)+1,1,0)-DATE(YEAR(A1),1,0))