reduce method ambiguities

src/datetime.jl

@@ -71,7 +71,7 @@ This type implements the calendar defined as "$($calendar)".
             return DT{T,Val(origin)}(args...)
         end
 
-        function $CFDateTime(t,units::AbstractString)
+        function $CFDateTime(t::Union{Number,Tuple},units::AbstractString)
             origintuple, factor, exponent = _timeunits(Tuple,units)
             instant = Period(t,factor,exponent)
             dt = $CFDateTime{typeof(instant),Val(origintuple)}(instant)
@@ -80,7 +80,7 @@ This type implements the calendar defined as "$($calendar)".
         $CFDateTime(y::Integer,args::Vararg{<:Integer,N}; kwargs...) where N = $CFDateTime(Int64,y,args...; kwargs...)
 
 
-        function $CFDateTime(p::Period,origintuple)
+        function $CFDateTime(p::Period,origintuple::Tuple)
             $CFDateTime{typeof(p),Val(origintuple)}(p)
         end
 
@@ -218,6 +218,7 @@ function -(dt1::DateTime,dt2::AbstractCFDateTime)
 end
 
 -(dt::AbstractCFDateTime,Δ::Period) = dt + (-Δ)
+-(dt::AbstractCFDateTime,Δ::Dates.CompoundPeriod) = dt + (-Δ)
 -(dt::AbstractCFDateTime,Δ) = dt + (-Δ)
 
 function ==(dt1::AbstractCFDateTime,dt2::AbstractCFDateTime)
@@ -261,3 +262,7 @@ end
 function show(io::IO,dt::T)  where T <: AbstractCFDateTime
     write(io, string(typeof(dt)), "(",string(dt),")")
 end
+
+
+# Missing support
+(-)(x::AbstractCFDateTime, y::Missing) = missing

src/period.jl

@@ -96,3 +96,8 @@ Dates.Millisecond(p::CFTime.Period{T, Val{1}(), Val{-3}()}) where T =
 function isless(p1::Period,p2::Period)
     return Dates.value(p1 - p2) < 0
 end
+
+
+# Missing support
+(==)(x::Period, y::Missing) = missing
+(==)(x::Missing, y::Period) = missing

test/test_resolution.jl

@@ -233,7 +233,7 @@ daysinmonth(DateTimeStandard,1582,10)
 daysinmonth(dt)
 
 DT = DateTimeStandard
-import CFTime: DateTimeStandard, _pad3, unwrap, _factor, _exponent, _type
+import CFTime: DateTimeStandard, unwrap, _factor, _exponent, _type