diff --git a/stdlib/Dates/src/types.jl b/stdlib/Dates/src/types.jl
index 4c338d5b765d7..3cbf2e4ca6e66 100644
--- a/stdlib/Dates/src/types.jl
+++ b/stdlib/Dates/src/types.jl
@@ -454,3 +454,5 @@ end
 
 Base.OrderStyle(::Type{<:AbstractTime}) = Base.Ordered()
 Base.ArithmeticStyle(::Type{<:AbstractTime}) = Base.ArithmeticWraps()
+
+Base.isnan(::AbstractTime) = false