Add time_and_date plugin. Use it for timezones and date formats around the bot.

backend/src/plugins/TimeAndDate/functions/getGuildTz.ts

@@ -0,0 +1,7 @@
+import { PluginData } from "knub";
+import { ZeppelinGuildConfig } from "../../../types";
+import { TimeAndDatePluginType } from "../types";
+
+export function getGuildTz(pluginData: PluginData<TimeAndDatePluginType>) {
+  return pluginData.config.get().timezone;
+}