v2 idea

Author: mtd321

stdlib/Dates/src/conversions.jl

@@ -25,7 +25,7 @@ DateTime(dt::TimeType) = convert(DateTime, dt)
 Convert a `DateTime` to a `Time`. The hour, minute, second, and millisecond parts of
 the `DateTime` are used to create the new `Time`. Microsecond and nanoseconds are zero by default.
 """
-Time(dt::TimeType) = convert(Time, dt)
+Time(dt::DateTime) = convert(Time, dt)
 
 Base.convert(::Type{DateTime}, dt::Date) = DateTime(UTM(value(dt) * 86400000))
 Base.convert(::Type{Date}, dt::DateTime) = Date(UTD(days(dt)))

stdlib/Dates/src/types.jl

@@ -420,6 +420,7 @@ end
 # Fallback constructors
 DateTime(y, m=1, d=1, h=0, mi=0, s=0, ms=0, ampm::AMPM=TWENTYFOURHOUR) = DateTime(Int64(y), Int64(m), Int64(d), Int64(h), Int64(mi), Int64(s), Int64(ms), ampm)
 Date(y, m=1, d=1) = Date(Int64(y), Int64(m), Int64(d))
+Time(t::Time) = t # avoid the less helpful fallback below.
 Time(h, mi=0, s=0, ms=0, us=0, ns=0, ampm::AMPM=TWENTYFOURHOUR) = Time(Int64(h), Int64(mi), Int64(s), Int64(ms), Int64(us), Int64(ns), ampm)
 
 # Traits, Equality