Set TimeZones as scalars for broadcasting (#30159)

Author: iamed2

stdlib/Dates/src/arithmetic.jl

@@ -83,5 +83,6 @@ end
 (-)(x::OrdinalRange{T}, y::OrdinalRange{T}) where {T<:TimeType} = Vector(x) - Vector(y)
 (-)(x::AbstractRange{T}, y::AbstractRange{T}) where {T<:TimeType} = Vector(x) - Vector(y)
 
-# Allow dates and times to broadcast as unwrapped scalars
+# Allow dates, times, and time zones to broadcast as unwrapped scalars
 Base.Broadcast.broadcastable(x::AbstractTime) = Ref(x)
+Base.Broadcast.broadcastable(x::TimeZone) = Ref(x)

stdlib/Dates/test/arithmetic.jl

@@ -472,6 +472,10 @@ end
         @test_throws MethodError (Dates.Month(1) + Dates.Day(1)) - t1
         @test_throws MethodError (Dates.Hour(1) + Dates.Minute(1)) - t3
     end
+    @testset "TimeZone" begin
+        # best we can get in Dates as there is no other tz functionality
+        @test ((a, b) -> now(typeof(a))).(UTC(), [1,2,3]) isa Vector{DateTime}
+    end
 end
 
 end