Rename to Crono

lib/crono/period.rb

@@ -0,0 +1,24 @@
+module Crono
+  class Period
+    def initialize(period, at: nil)
+      @period = period
+      @at_hour, @at_min = parse_at(at) if at
+    end
+
+    def next
+      @period.from_now.change({hour: @at_hour, min: @at_min}.compact)
+    end
+
+    def parse_at(at)
+      case at
+      when String
+        time = Time.parse(at)
+        return time.hour, time.min
+      when Hash
+        return at[:hour], at[:min]
+      else
+        raise "Unknown 'at' format"
+      end
+    end
+  end
+end