add long validity test

test/test_validity.jl

@@ -0,0 +1,60 @@
+using CFTime
+using Test
+
+include("reference_algorithm.jl")
+
+
+test_years(T,max_year::Integer) = test_years(T,-max_year:max_year)
+
+function test_years(T,yearrange::AbstractRange)
+    nsuccess = Int128(0)
+    fails = Int64[]
+
+    for year = yearrange
+        if (year != 0) || ((year == 0) && CFTime._hasyear0(T))
+            for Z in (CFTime.datenum(T,year,1,1):1:CFTime.datenum(T,year+1,1,1))[1:end-1]
+                MYMD = CFTime.datetuple_ymd(T,Z);
+                RYMD = Reference.datetuple_ymd(T,Z);
+
+                if MYMD == RYMD
+                    nsuccess += 1
+                else
+                    push!(fails,Z)
+                end
+
+                Z2 = CFTime.datenum(T,MYMD...)
+
+                if Z == Z2
+                    nsuccess += 1
+                else
+                    push!(fails,Z)
+                end
+            end
+        end
+    end
+    return (nsuccess,fails)
+end
+
+
+yearrange = 1000:3000
+yearrange = 1900:2000
+
+if length(ARGS) > 0
+    param = parse.(Int64,split(ARGS[1],','))
+    yearrange = param[1]:param[2]
+end
+
+@show yearrange
+
+for T in [DateTimeStandard, DateTimeJulian, DateTimeProlepticGregorian,
+          DateTimeAllLeap, DateTimeNoLeap, DateTime360Day]
+
+    nsuccess,fails = @time test_years(T,yearrange)
+
+    println(T," success: ",nsuccess)
+    println(T," fails: ",length(fails))
+
+    if length(fails) > 0
+        println.(fails);
+    end
+end