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

backend/src/data/GuildMemberTimezones.ts

@@ -0,0 +1,48 @@
+import { BaseGuildRepository } from "./BaseGuildRepository";
+import { MemberTimezone } from "./entities/MemberTimezone";
+import { getRepository, Repository } from "typeorm/index";
+import { connection } from "./db";
+
+export class GuildMemberTimezones extends BaseGuildRepository {
+  protected memberTimezones: Repository<MemberTimezone>;
+
+  constructor(guildId: string) {
+    super(guildId);
+    this.memberTimezones = getRepository(MemberTimezone);
+  }
+
+  get(memberId: string) {
+    return this.memberTimezones.findOne({
+      guild_id: this.guildId,
+      member_id: memberId,
+    });
+  }
+
+  async set(memberId, timezone: string) {
+    await connection.transaction(async entityManager => {
+      const repo = entityManager.getRepository(MemberTimezone);
+      const existingRow = await repo.findOne({
+        guild_id: this.guildId,
+        member_id: memberId,
+      });
+
+      if (existingRow) {
+        await repo.update(
+          {
+            guild_id: this.guildId,
+            member_id: memberId,
+          },
+          {
+            timezone,
+          },
+        );
+      } else {
+        await repo.insert({
+          guild_id: this.guildId,
+          member_id: memberId,
+          timezone,
+        });
+      }
+    });
+  }
+}