Support signbit(::Dates.Period) (#51073)

Author: jishnub

stdlib/Dates/src/periods.jl

@@ -102,6 +102,7 @@ div(x::Period, y::Period, r::RoundingMode) = div(promote(x, y)..., r)
 Base.gcdx(a::T, b::T) where {T<:Period} = ((g, x, y) = gcdx(value(a), value(b)); return T(g), x, y)
 Base.abs(a::T) where {T<:Period} = T(abs(value(a)))
 Base.sign(x::Period) = sign(value(x))
+Base.signbit(x::Period) = signbit(value(x))
 
 # return (next coarser period, conversion factor):
 coarserperiod(::Type{P}) where {P<:Period} = (P, 1)

stdlib/Dates/test/periods.jl

@@ -30,6 +30,9 @@ using Test
     @test sign(t) == sign(t2) == 1
     @test sign(-t) == sign(-t2) == -1
     @test sign(Dates.Year(0)) == 0
+    @test signbit(t) == signbit(t2) == false
+    @test signbit(-t) == signbit(-t2) == true
+    @test signbit(Dates.Year(0)) == false
 end
 @testset "div/mod/gcd/lcm/rem" begin
     @test Dates.Year(10) % Dates.Year(4) == Dates.Year(2)