fix #3701, calculation wrong, added testcase, ics, config (#3702)

fixes #3701 

offset calculation wrong when user looking back at east coast event

added testcase

tests/configs/modules/calendar/chicago-looking-at-ny-recurring.js

@@ -0,0 +1,33 @@
+let config = {
+	address: "0.0.0.0",
+	ipWhitelist: [],
+
+	timeFormat: 24,
+	modules: [
+		{
+			module: "calendar",
+			position: "bottom_bar",
+			config: {
+				fade: false,
+				urgency: 0,
+				dateFormat: "Do.MMM, HH:mm",
+				fullDayEventDateFormat: "Do.MMM",
+				timeFormat: "absolute",
+				getRelative: 0,
+				maximumNumberOfDays: 28,
+				showEnd: true,
+				calendars: [
+					{
+						maximumEntries: 100,
+						url: "http://localhost:8080/tests/mocks/chicago-nyedge.ics"
+					}
+				]
+			}
+		}
+	]
+};
+
+/*************** DO NOT EDIT THE LINE BELOW ***************/
+if (typeof module !== "undefined") {
+	module.exports = config;
+}