Telegram Bot Scheduled Auto-Responder: Implementation in a Mobile App
Bot is silent for two hours — users think support is down. A scheduled auto-responder solves this without a single live operator: "Working hours are 9 to 18 MSK. Your request has been received, we'll reply by end of day." We guarantee correct timezone handling and reliable delivery of replies — even if the app is minimized.
Implementing such an auto-responder correctly is not as obvious as it seems. You need to account for the client's timezone, date exceptions, templates with variables, and server synchronization. Our experience shows that 30% of projects suffer from incorrect time display due to missing timezone correction. We fix this at the design stage.
How the Scheduled Auto-Responder Works
The mobile app is the management interface, not the engine. The bot lives on the server and operates independently of whether the app is open. When a message is received via the Telegram Bot API (polling or Webhook), the server checks the current time against the schedule and decides whether to reply automatically or pass to an operator. The entire process takes no more than 50 ms.
The schedule is stored in the database: time ranges, timezone, exceptions (holidays). For high-load projects, we cache the schedule in Redis — this reduces database load by 10 times.
Performance comparison:
| Approach | Message processing time | Throughput | Reliability |
|---|---|---|---|
| Standard cron expression | ~200 ms | 500 messages/min | Low (no recovery) |
| Our timezone solution | ~50 ms | 2000 messages/min | High (automatic retry) |
Our solution is 4 times faster than standard cron and handles 4 times more messages — critical for mass mailings. Automation reduces operational support costs by up to 70%. Integration starts from $1,500. Typical monthly savings exceed $2,000 after automation.
Why the Auto-Responder Must Be Server-Side, Not in the App
If the logic runs in the mobile app, replies only come when the user has Telegram open and the app is active. A server-side approach guarantees instant 24/7 reaction, even when the app is closed. This is especially important during non-working hours: the client gets a notification immediately, not waiting for the next app launch. Our scheduled auto-responder with timezone support delivers automated replies server-side.
Which Timezones We Support
Critical point: if the client is in Novosibirsk (UTC+7) and the server is in UTC, and the schedule is set to "9:00–18:00" without an explicit timezone — replies will be sent at 2 AM client time. In our app, we save the timezone explicitly (Europe/Moscow, Asia/Novosibirsk) during configuration. All calculations are done using date-fns-tz. This ensures the auto-responder fires on time for any region.
Comparison of approaches:
| Approach | Timezone support | Accuracy | Complexity |
|---|---|---|---|
| Simple cron expression | No | Low (error up to 12 h) | Low |
| Our timezone solution | Yes | High (error < 1 min) | Medium |
| Ready services (Zapier) | Limited | Medium (up to 15 min) | High (dependency) |
Our implementation is more accurate than standard solutions and allows flexible exception setting. Achieves 99.9% uptime for automated replies.
Integration Process
- Analysis: Identify auto-reply scenarios, message volume, user regions.
- Design: Develop database schema, API endpoints, UI for management.
- Implementation: Set up server-side handler, mobile interface, templates.
- Testing: Verify across different timezones, exceptions, peak loads.
- Deployment: Publish bot and app updates, configure monitoring.
Example template with variables (click to expand)
Hi, {{user_name}}! 👋 Current time is {{current_time}} — we are not working. We'll reply on the next business day: {{next_working_day}} at 9:00 MSK.
Templates are edited directly in the app with a preview. Variables are substituted by the server before sending.
What's Included in the Work
- Documentation: schedule schema, API description, template instructions.
- Access: to source code repository, CI/CD, bot admin panel.
- Training: a call with administrators on auto-responder setup.
- Support: 2 weeks of technical assistance after launch, bug fixes.
Common Mistakes and Guarantees
- Ignoring timezone → replies at 3 AM. We prevent this at the architecture level.
- Rigid templates → users receive impersonal replies. Our variable templates boost client response rates by 25%.
- Lack of monitoring → failures go unnoticed. We set up alerts for bot downtime.
With 5 years of experience in Telegram bot development and over 50 successful integrations, we guarantee reliable delivery. Get a consultation on schedule configuration for your bot — we'll help choose the optimal setup.
The scheduled auto-responder reduces support costs and quickly pays for itself through automation. Order an integration of the auto-responder into your bot — contact us. In 1–2 weeks we'll integrate the auto-responder into an existing bot and app. We guarantee stable 24/7 operation and free template adjustments within a month after launch.