Age on a specific date from DOB

Hi cfindling ,

I agreed with AlexisOlson 's suggestion to use DATEDIFF() to calculate the Age:

Measure = DATEDIFF(MAX('person'[date of birth]),MAX('vaccine'[vaccine administered date]),YEAR)

Column = 
var _vaccine=LOOKUPVALUE('vaccine'[vaccine administered date],[person ],[person])
return DATEDIFF([date of birth],_vaccine,YEAR)

If it does not work, you may try to do it in Power Query, below is the whole M syntax:

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("Hcu5CQAxDATAXjY2rLUnfCi8pwuh/tuwUTowmXgwYBGLJupCjcTbdDudUsvX4kGblDf9hzSneOZC1QY=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [person = _t, #"date of birth" = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"person", type text}, {"date of birth", type date}}),
    #"Merged Queries" = Table.NestedJoin(#"Changed Type", {"person"}, vaccine, {"person "}, "vaccine", JoinKind.LeftOuter),
    #"Expanded vaccine" = Table.ExpandTableColumn(#"Merged Queries", "vaccine", {"vaccine administered date"}, {"vaccine administered date"}),
    #"Inserted Age" = Table.AddColumn(#"Expanded vaccine", "Age", each [vaccine administered date] - [date of birth]),
    #"Calculated Total Years" = Table.TransformColumns(#"Inserted Age",{{"Age", each Duration.TotalDays(_) / 365, type number}}),
    #"Rounded Down" = Table.TransformColumns(#"Calculated Total Years",{{"Age", Number.RoundDown, Int64.Type}})
in
    #"Rounded Down"

Best Regards,
Eyelyn Qin
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