diff --git a/stdlib/Dates/src/ranges.jl b/stdlib/Dates/src/ranges.jl
index c4299c7b02be5..c253e211edb98 100644
--- a/stdlib/Dates/src/ranges.jl
+++ b/stdlib/Dates/src/ranges.jl
@@ -15,12 +15,13 @@ function len(a, b, c)
     i = guess(a, b, c)
     v = lo + st * i
     prev = v  # Ensure `v` does not overflow
+    hi -= st # Prevent overshooting
     while v <= hi && prev <= v
         prev = v
         v += st
         i += 1
     end
-    return i - 1
+    return i
 end
 Base.length(r::StepRange{<:TimeType}) = isempty(r) ? Int64(0) : len(r.start, r.stop, r.step) + 1
 # Period ranges hook into Int64 overflow detection
diff --git a/stdlib/Dates/src/types.jl b/stdlib/Dates/src/types.jl
index e1f7f900bff51..1b941764fa4c6 100644
--- a/stdlib/Dates/src/types.jl
+++ b/stdlib/Dates/src/types.jl
@@ -249,8 +249,11 @@ function DateTime(y::Int64, m::Int64=1, d::Int64=1,
     return DateTime(UTM(rata))
 end
 
+const DATETIME_YEAR_TYPEMAX = 146138512
+const DATETIME_YEAR_TYPEMIN = -146138511
 function validargs(::Type{DateTime}, y::Int64, m::Int64, d::Int64,
                    h::Int64, mi::Int64, s::Int64, ms::Int64, ampm::AMPM=TWENTYFOURHOUR)
+    DATETIME_YEAR_TYPEMIN <= y <= DATETIME_YEAR_TYPEMAX || return ArgumentError("Year: $y out of range ($(DATETIME_YEAR_TYPEMIN):$DATETIME_YEAR_TYPEMAX)")
     0 < m < 13 || return ArgumentError("Month: $m out of range (1:12)")
     0 < d < daysinmonth(y, m) + 1 || return ArgumentError("Day: $d out of range (1:$(daysinmonth(y, m)))")
     if ampm == TWENTYFOURHOUR # 24-hour clock
@@ -278,9 +281,12 @@ function Date(y::Int64, m::Int64=1, d::Int64=1)
     return Date(UTD(totaldays(y, m, d)))
 end
 
+const DATE_YEAR_TYPEMAX = 252522163911149
+const DATE_YEAR_TYPEMIN = -252522163911150
 function validargs(::Type{Date}, y::Int64, m::Int64, d::Int64)
     0 < m < 13 || return ArgumentError("Month: $m out of range (1:12)")
     0 < d < daysinmonth(y, m) + 1 || return ArgumentError("Day: $d out of range (1:$(daysinmonth(y, m)))")
+    DATE_YEAR_TYPEMIN <= y <= DATE_YEAR_TYPEMAX || return ArgumentError("Year: $y out of range ($(DATE_YEAR_TYPEMIN):$DATE_YEAR_TYPEMAX)")
     return nothing
 end
 
@@ -461,10 +467,10 @@ Base.zero(::Type{Time}) = Nanosecond(0)
 Base.zero(::T) where T <: TimeType = zero(T)::Period
 
 
-Base.typemax(::Union{DateTime, Type{DateTime}}) = DateTime(146138512, 12, 31, 23, 59, 59)
-Base.typemin(::Union{DateTime, Type{DateTime}}) = DateTime(-146138511, 1, 1, 0, 0, 0)
-Base.typemax(::Union{Date, Type{Date}}) = Date(252522163911149, 12, 31)
-Base.typemin(::Union{Date, Type{Date}}) = Date(-252522163911150, 1, 1)
+Base.typemax(::Union{DateTime, Type{DateTime}}) = DateTime(DATETIME_YEAR_TYPEMAX, 12, 31, 23, 59, 59)
+Base.typemin(::Union{DateTime, Type{DateTime}}) = DateTime(DATETIME_YEAR_TYPEMIN, 1, 1, 0, 0, 0)
+Base.typemax(::Union{Date, Type{Date}}) = Date(DATE_YEAR_TYPEMAX, 12, 31)
+Base.typemin(::Union{Date, Type{Date}}) = Date(DATE_YEAR_TYPEMIN, 1, 1)
 Base.typemax(::Union{Time, Type{Time}}) = Time(23, 59, 59, 999, 999, 999)
 Base.typemin(::Union{Time, Type{Time}}) = Time(0)
 # Date-DateTime promotion, isless, ==
diff --git a/stdlib/Dates/test/types.jl b/stdlib/Dates/test/types.jl
index 35a793867dc5a..21b02913b4387 100644
--- a/stdlib/Dates/test/types.jl
+++ b/stdlib/Dates/test/types.jl
@@ -151,15 +151,19 @@ end
     @test_throws InexactError Dates.Date(1.2f0, 1.f0, 1.f0)
     @test_throws InexactError Dates.Date(3//4, Rational(1), Rational(1)) == test
 
-    # Months, days, hours, minutes, seconds, and milliseconds must be in range
+    # Years, months, days, hours, minutes, seconds, and milliseconds must be in range
     @test_throws ArgumentError Dates.Date(2013, 0, 1)
     @test_throws ArgumentError Dates.Date(2013, 13, 1)
     @test_throws ArgumentError Dates.Date(2013, 1, 0)
     @test_throws ArgumentError Dates.Date(2013, 1, 32)
+    @test_throws ArgumentError Dates.Date(year(typemax(Date))+1, 1, 1)
+    @test_throws ArgumentError Dates.Date(year(typemin(Date))-1, 1, 32)
     @test_throws ArgumentError Dates.DateTime(2013, 0, 1)
     @test_throws ArgumentError Dates.DateTime(2013, 13, 1)
     @test_throws ArgumentError Dates.DateTime(2013, 1, 0)
     @test_throws ArgumentError Dates.DateTime(2013, 1, 32)
+    @test_throws ArgumentError Dates.DateTime(year(typemax(DateTime))+1, 1, 1)
+    @test_throws ArgumentError Dates.DateTime(year(typemin(DateTime))-1, 1, 32)
     @test_throws ArgumentError Dates.DateTime(2013, 1, 1, 25)
     @test_throws ArgumentError Dates.DateTime(2013, 1, 1, -1)
     @test_throws ArgumentError Dates.DateTime(2013, 1, 1, 0, -1)