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

backend/src/plugins/TimeAndDate/commands/SetTimezoneCmd.ts

@@ -0,0 +1,17 @@
+import { timeAndDateCmd } from "../types";
+import { commandTypeHelpers as ct } from "../../../commandTypes";
+import { sendSuccessMessage } from "../../../pluginUtils";
+
+export const SetTimezoneCmd = timeAndDateCmd({
+  trigger: "timezone",
+  permission: "can_set_timezone",
+
+  signature: {
+    timezone: ct.timezone(),
+  },
+
+  async run({ pluginData, message, args }) {
+    await pluginData.state.memberTimezones.set(message.author.id, args.timezone);
+    sendSuccessMessage(pluginData, message.channel, `Your timezone is now set to **${args.timezone}**`);
+  },
+});