Scheduling

Control when watches run with flexible time-based scheduling and timezone support

Scheduling

Scheduling allows you to control exactly when changedetection.io checks websites for changes. Set specific time windows, limit checks to business hours, schedule checks in different timezones, or combine with check intervals for precise control.

What is Scheduling?

The scheduler lets you define time windows when change detection should run. This is different from check intervals:

Check Interval

How often to check

Example: Every 6 hours

Schedule

When checks can run

Example: Only weekdays 9 AM - 5 PM

Scheduling + Intervals work together

• Check Interval: “Check every 30 minutes”
• Schedule: “Only run Monday-Friday, 9 AM to 5 PM EST”

Result: Checks every 30 minutes, but only during weekday business hours in Eastern Time.

Why Use Scheduling?

Business Hours Only

Monitor job postings or business sites only during work hours

Reduce Load

Avoid checking sites during maintenance windows or off-peak times

Timezone Matching

Check foreign sites during their business hours

Peak Time Monitoring

Focus checks during high-activity periods (e.g., sale hours)

Setting Up Scheduling

Global Scheduling (Default for All Watches)

1. Go to Settings

   Navigate to Settings → Requests tab

2. Find Schedule Section

   Scroll to “Time scheduler” section

3. Enable Scheduler

   Check “Use time scheduler”

4. Configure Days and Times

   Set start times and durations for each day of the week

5. Set Timezone (Optional)

   Enter a timezone name (e.g., America/New_York, Europe/London)

Per-Watch Scheduling

Override global scheduling for specific watches:

1. Edit Watch

   Click Edit on any watch

2. Uncheck 'Use Global Settings'

   Uncheck “Use global settings for time between check and scheduler”

3. Configure Time Schedule

   Scroll to “Time Schedule” section and configure days/times

Schedule Configuration

Day Settings

For each day of the week, configure:

Setting	Description	Example
Enabled	Enable/disable checking on this day	✅ Monday enabled
Start At	Time to begin checking	09:00
Run duration (Hours)	How many hours to check	8 hours
Run duration (Minutes)	Additional minutes	30 minutes

Example configuration for Monday:

✅ Enabled
Start At: 09:00
Run duration: 8 hours, 30 minutes

Result: Checks run Monday from 9:00 AM to 5:30 PM

Quick Presets

Use the quick-select buttons for common schedules:

Business Hours

Automatically sets:

• Monday-Friday: 9:00 AM - 5:00 PM (8 hours)
• Saturday-Sunday: Disabled

Perfect for monitoring job boards, business websites, or corporate pages.

Weekends

Automatically sets:

• Monday-Friday: Disabled
• Saturday-Sunday: 12:00 AM - 12:00 AM (24 hours)

Perfect for monitoring weekend sales, events, or promotions.

Timezone Configuration

Setting Timezone

Field: “Optional timezone to run in”

Enter a valid timezone name from the tz database:

Common timezones:

• America/New_York (Eastern Time)
• America/Chicago (Central Time)
• America/Los_Angeles (Pacific Time)
• Europe/London (GMT/BST)
• Europe/Paris (CET/CEST)
• Asia/Tokyo (JST)
• Australia/Sydney (AEST/AEDT)

If not set: Uses the server’s local timezone.

Timezone format matters

Use the full tz database name:

• ✅ America/New_York
• ❌ EST (not accepted)
• ❌ Eastern Time (not accepted)

Incorrect timezone names will cause validation errors.

How Scheduling Works

Schedule + Check Interval Example

Configuration:

Check Interval: Every 1 hour

Schedule:
  Monday: 09:00 - 17:00 (8 hours)
  Tuesday: 09:00 - 17:00 (8 hours)
  Wednesday-Sunday: Disabled

Behavior:

• Monday 9 AM: Check runs ✅
• Monday 10 AM: Check runs ✅
• Monday 11 AM: Check runs ✅
• …
• Monday 5 PM: Check runs ✅
• Monday 6 PM: Skipped ❌ (outside schedule)
• Tuesday 9 AM: Check runs ✅
• Wednesday: All checks skipped ❌

Outside Schedule Window

When a check is scheduled to run but falls outside the schedule window:

1. Check is skipped - No request is made
2. Next check waits - Respects the check interval
3. Resumes when window opens - First check runs at next scheduled window

Checks don’t queue up

If checks are skipped over the weekend, they don’t all run at once on Monday. The normal check interval resumes when the schedule window opens.

Common Scheduling Scenarios

Business Hours Only (Monday-Friday, 9-5)

Use case: Monitor job postings that only update during business hours

Configuration:

✅ Use time scheduler

Monday-Friday:
  ✅ Enabled
  Start At: 09:00
  Duration: 8 hours

Saturday-Sunday:
  ❌ Disabled

Timezone: America/New_York

Combine with:

• Check interval: Every 30 minutes
• Result: Checks every 30 min, Mon-Fri 9 AM-5 PM EST

Weekend Sales Monitoring

Use case: Track weekend-only flash sales or promotions

Configuration:

✅ Use time scheduler

Monday-Friday:
  ❌ Disabled

Saturday:
  ✅ Enabled  
  Start At: 00:00
  Duration: 24 hours

Sunday:
  ✅ Enabled
  Start At: 00:00  
  Duration: 24 hours

Combine with:

• Check interval: Every 15 minutes
• Result: Checks every 15 min, weekends only

International Site Monitoring

Use case: Monitor a Japanese e-commerce site during their business hours

Configuration:

✅ Use time scheduler

Monday-Friday:
  ✅ Enabled
  Start At: 09:00
  Duration: 10 hours

Timezone: Asia/Tokyo

Result: Checks run 9 AM - 7 PM Japan time, regardless of your server’s location.

Peak Shopping Hours

Use case: Monitor product restocks during peak shopping times

Configuration:

✅ Use time scheduler

Every day:
  ✅ Enabled
  Start At: 08:00
  Duration: 4 hours

AND

Every day:
  Start At: 17:00  
  Duration: 5 hours

Note: You can only set one time window per day, so you’d need separate watches for morning and evening windows, or use a longer duration (8 AM - 10 PM).

Avoid Maintenance Windows

Use case: Don’t check a site that’s down for maintenance 2-4 AM daily

Configuration:

✅ Use time scheduler

Every day:
  ✅ Enabled
  Start At: 04:00
  Duration: 22 hours

Result: Checks skip 2 AM - 4 AM, run rest of the day.

Advanced Scheduling Techniques

Combining Multiple Schedules with Tags

Create different schedules for different groups of watches:

1. Create Tags

   • Tag: “Business Hours Watches”
   • Tag: “24/7 Critical Watches”
   • Tag: “Weekend Only”
2. Configure Per-Watch Schedules

   Apply different schedules to watches in each tag

3. Manage from Dashboard

   Filter by tag to see which watches are active at different times

Reduced Frequency During Off-Hours

Scenario: Check every 15 minutes during business hours, every 2 hours overnight

Solution: Create two watches for the same URL:

Watch 1: “Product - Business Hours”

Check Interval: Every 15 minutes
Schedule: Mon-Fri, 9 AM - 5 PM

Watch 2: “Product - Off-Hours”

Check Interval: Every 2 hours  
Schedule: Mon-Fri, 5 PM - 9 AM + Weekends

Mute one watch’s notifications

To avoid duplicate notifications, mute one of the watches and only receive alerts from the other.

Seasonal Schedules

For seasonal monitoring (e.g., holiday shopping, tax season):

1. Enable aggressive scheduling during the season
2. Disable or reduce frequency outside the season
3. Use tags to quickly enable/disable seasonal watches

Troubleshooting

Watch Not Running

Check is outside schedule window

Verify:

• Current time is within the scheduled window
• Day of week is enabled
• Timezone is correct (if set)

Check:

• Look at “Last check” time on watch
• If last check was before the schedule window, next check will wait until window opens

Duration is too short

Problem: Duration doesn’t cover the check interval

Example:

• Check interval: Every 2 hours
• Schedule: Start 9:00, Duration 1 hour

Result: Only one check at 9 AM, next check at 11 AM is outside window

Solution: Increase duration to at least match check interval, ideally longer

Timezone mismatch

Symptom: Schedule seems to run at wrong times

Cause: Timezone setting doesn’t match intended timezone

Fix:

• Verify timezone name is correct
• Check current time in that timezone
• Test with server’s local timezone first (leave timezone blank)

Schedule Not Saving

Error: “Invalid timezone name”

Solution:

• Use tz database names: America/New_York not EST
• Check spelling and capitalization
• Leave timezone blank to use server time

Unexpected Check Times

Problem: Checks run at unexpected times despite schedule

Possible causes:

1. Global vs per-watch conflict:

   • Check if watch is using global settings
   • Verify which schedule is actually active

2. Check interval too long:

   • If interval > duration, only one check may run per window

3. Jitter enabled:

   • Random jitter adds ± seconds to check times
   • Check global settings for jitter configuration

Best Practices

Match check interval to schedule duration

Ensure your schedule duration is long enough for multiple checks.

Good:

• Interval: 30 minutes
• Duration: 8 hours
• Result: 16 checks per day

Bad:

• Interval: 2 hours
• Duration: 1 hour
• Result: Only 1 check per day

Use timezone for international sites

Always set timezone when monitoring sites in different regions.

Example: Monitoring a UK site from a US server:

Timezone: Europe/London
Schedule: Mon-Fri, 9:00 AM - 5:00 PM

Ensures checks run during UK business hours.

Test schedule before deploying

After setting a schedule:

1. Note the current time in the configured timezone
2. Verify it’s within the schedule window
3. Click “Check now” to test
4. Wait for next interval and confirm automatic check runs

Use global schedule as default

Set a sensible global schedule (e.g., business hours) and override only for special cases.

This makes managing large numbers of watches easier.

Document your schedules

Use watch titles or tags to indicate schedules:

• “Product - Business Hours Only”
• Tag: “9-5-monitoring”

Makes it easier to understand which watches run when.

Scheduling vs. Other Features

Scheduling vs. Check Interval

Feature	Purpose	Example
Check Interval	How often to check	Every 30 minutes
Scheduling	When checks can run	Only weekdays 9-5
Combined	Precise control	Every 30 min, weekdays 9-5

Scheduling vs. Conditional Monitoring

Feature	When to Use
Scheduling	Control when checks run based on time/day
Conditional Monitoring	Control when notifications send based on content
Both	”Check during business hours, notify only if price < $50”

Related Features

Check Intervals

Configure how often watches run

Conditional Monitoring

Filter notifications based on content conditions

Next Steps

1. Set Up Your First Schedule

   Configure business hours scheduling for a test watch

2. Test Timezone Settings

   Try monitoring an international site during their business hours

3. Optimize Check Frequency

   Combine scheduling with check intervals for efficient monitoring