How I Built a Timezone-Aware Email Automation Using n8n + OpenAI

Ann Chisom Sokwueaku — Tue, 24 Jun 2025 11:32:20 +0000

I recently built an automated email outreach system using n8n + OpenAI, and it only sends emails during the lead's local business hours.

Here’s what the flow looks like:

This is the code used to check for the

return items.map(item => {
  // Use timezone from assistant's response (e.g. item.json.message.content)
  const timezone = item.json.message?.content || "UTC";

  try {
    const now = new Date();
    const formatter = new Intl.DateTimeFormat('en-US', {
      timeZone: timezone,
      hour: 'numeric',
      hour12: false,
    });

    const parts = formatter.formatToParts(now);
    const hour = parseInt(parts.find(p => p.type === 'hour')?.value || "0", 10);

    return {
      json: {
        ...item.json,
        currentHour: hour,
        isWithinBusinessHours: hour >= 8 && hour < 18,
        timezoneChecked: timezone
      }
    };
  } catch (err) {
    return {
      json: {
        ...item.json,
        error: `Invalid timezone: ${timezone}`,
        currentHour: null,
        isWithinBusinessHours: false,
        timezoneChecked: timezone
      }
    };
  }
});

current time `

Why I Built This

Sending cold emails at 3 AM in the recipient's timezone? Bad idea.

This automation ensures:

Higher open rates
Professional timing
Less chance of being marked as spam

Tools Used

n8n – Automation logic and orchestration
Google Sheets – Where I store leads
OpenAI GPT – Detect timezone + generate emails
Custom Delay Logic – Wait until local business hours

Workflow Steps

Read leads from Google Sheets
Check status (if they’ve already been emailed)
Use OpenAI to infer the timezone (from country or city)
Check the current hour in their timezone
If too early/late, wait for 3 hours
Once it’s a good time, generate a personalized email
Send it, log it, and notify me of errors

Output

Emails only go out between 9 AM–5 PM local time
Each one is AI-personalized
Everything is logged in Sheets
I get notified once there is an error

Feedback?
I would love to hear:

How do you scale or modularize this
How to make it more robust for thousands of leads
If there's a better approach for timezone detection

Let’s connect!
Thanks for reading

DEV Community: Ann Chisom Sokwueaku

How I Built a Timezone-Aware Email Automation Using n8n + OpenAI