I am using Mathematica 10.0.2

(* This line does not function correctly *)

date1 = PlanetaryMoonData["Moon", EntityProperty["PlanetaryMoon", "RiseTime", {"Date" -> #}]] & /@DateObject[{2015, 4, 4}]

(* Next code functions correctly *)

moon = EntityList[EntityClass["PlanetaryMoon", "EarthMoon"]]
ret = PlanetaryMoonData[moon, EntityProperty["PlanetaryMoon", "RiseTime", {"Date" -> #}]] & /@DateObject[{2015, 4, 4}]
ret = ret[[1]]
ret = ret[[1]]

Out[38]= DateObject[Missing["NotAvailable"]]
Out[39]= {Entity["PlanetaryMoon", "Moon"]}
Out[40]= DateObject[{DateObject[{2015, 4, 4}, TimeObject[{18, 9}], TimeZone -> 8.]}]
Out[41]= {DateObject[{2015, 4, 4}, TimeObject[{18, 9}], TimeZone -> 8.]}
Out[42]= DateObject[{2015, 4, 4}, TimeObject[{18, 9}], TimeZone -> 8.]

(* This code functions correctly *)

consID = ConstellationData[] // Sort;
sirius = ConstellationData[consID[[14]], "BrightStars"][[1]];
procyon = ConstellationData[consID[[15]], "BrightStars"][[1]];

(* This line does not function correctly *)

StarData[procyon, EntityProperty["Star", "Altitude", {"Date" -> ret, "Location" -> GeoPosition[{23.73, 120.3}]}]

Thanks for your help.