add src/rounding.jl

src/rounding.jl

@@ -0,0 +1,34 @@
+
+
+
+function round(::Type{DateTime}, dt::AbstractCFDateTime,r = RoundNearestTiesUp)
+    origin = _origin_period(dt)
+    t = dt.instant + (origin + DATETIME_OFFSET)
+
+    t_ms =
+        if 3+_exponent(t) > 0
+            t.duration * _factor(t) * 10^(3+_exponent(t))
+        else
+            t.duration * _factor(t) / 10^(-3-_exponent(t))
+        end
+
+    t_ms_rounded = round(Int64,t_ms,r)
+    return DateTime(UTInstant{Millisecond}(Dates.Millisecond(t_ms_rounded)))
+end
+
+
+function Base.floor(dt::DateTimeStandard,p::Period)
+    origintuple = _origintuple(dt)
+    origin = _origin_period(dt)
+    t = dt.instant + origin
+
+    tt = t - mod(t,p)
+
+    ttt = tt - origin
+
+    return DateTimeStandard{typeof(ttt), Val(origintuple)}(ttt)
+end
+
+function Base.floor(dt::DateTimeStandard,p::Dates.TimePeriod)
+    floor(dt,convert(Period,p))
+end