Tags: Time Operators

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Overview

• Abandoned cart: Remind users who haven’t checked out after a certain time
• Event reminders: Message users before a scheduled appointment or renewal date
• Milestones: Follow up when users haven’t completed an action by a deadline
• Birthdays: Send messages on (or around) a user’s birthday

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When should I use this?

• Send messages relative to an event, not at a fixed calendar time
• Create moving time windows (for example, “24–48 hours after”)
• Reuse the same logic for many users with different dates
• Continuously evaluate eligibility as time passes

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Tags vs Custom Events

• Use Tags when you want to store the latest known timestamp on the user (for example, cart_updated_at or subscription_expires_at) and segment off that value over time.
• Use Custom Events when you want to record each event occurrence (with properties) and trigger Journeys based on real-time behavior.

• Tags for user properties that are static and don’t change often
• Custom Events for real-time scenarios, complex segmentation, and more sophisticated journey workflows

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Quick reference

1. Convert the event date into a Unix timestamp in seconds.
2. Set a Tag where the key is the event name and the value is the timestamp as a string (e.g., 'event_date': '1739145600').
3. Create a segment using the Time Elapsed Greater Than operator:
   • After a past date using Time Elapsed Greater Than operator with a positive value
   • Before a future date using Time Elapsed Greater Than operator with a negative value

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Send messages after a past event

1

Store the timestamp when the event happens

When the user updates their cart, save the current time as a Unix timestamp (in seconds):

// SDK example
const timestampSeconds = String(Math.floor(Date.now() / 1000));
OneSignal.User.addTag("current_time", timestampSeconds);

Use seconds (10 digits), not milliseconds (13 digits).

2

Create a segment

1. Go to Audience > Segments
2. Add a User Tag filter
3. Set Key to current_time
4. Choose Time Elapsed Greater Than
5. Set Value to 1 day (or 24 hours or 86400 seconds)

3

Add an upper limit (Recommended)

Without an upper limit, users stay in the segment forever. Add a second filter to create a window:

• Time Elapsed Greater Than 24 hours
• Time Elapsed Less Than 48 hours

Now users are only in the segment between 24-48 hours after the event.

4

Use the segment in a Journey

Create a Journey that targets your segment to automate the messaging.

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Send messages before a future event

1. Store the future date as a Unix timestamp tag (e.g., 'future_date': '1739145600')
2. Create a segment with Time Elapsed Greater Than and your desired entry time as a negative value
   • Example: -2 days (or -172800 seconds)

3. Add an upper limit using the same Time Elapsed Greater Than operator with a negative value of a closer time
   • Example: -1 day (or -86400 seconds)

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Example: Birthday messages

1

Store the next birthday timestamp

Calculate and store the user’s next upcoming birthday:

function getNextBirthday(month, day) {
  // month: 0-11 (Jan=0), day: 1-31
  const now = new Date();
  let birthday = new Date(now.getFullYear(), month, day);

  if (birthday <= now) {
    birthday = new Date(now.getFullYear() + 1, month, day);
  }

  return String(Math.floor(birthday.getTime() / 1000));
}

// Example: January 15th birthday
OneSignal.User.addTag("birthday", getNextBirthday(0, 15));

2

Create a birthday segment

• User Tag: birthday
• Time Elapsed Greater Than: 0 seconds

Users enter the segment once their birthday timestamp passes.

3

Set up a recurring Journey

1. Create a Journey targeting your birthday segment
2. Set re-entry to 52 weeks so users can re-enter next year
3. Update the birthday tag to next year’s date after sending (in your backend or Journey)

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FAQ

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How does the math work? (technical details)

time_elapsed = current_time - tag_timestamp

• Past timestamps → positive values
• Future timestamps → negative values

• Time Elapsed Greater Than X: matches when elapsed > X
• Time Elapsed Less Than X: matches when elapsed < X

-2,592,000 < 172,800  →  true (matches)

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How can I test?

1. Find your user via the External ID, Subscription ID, Email or Phone number. See Find and set Test Users for details on finding your user.
2. Get a timestamp in seconds of the current date and a future date (5 minutes from now).
3. Set two tags with the keys ‘current_time’ and ‘future_time’ and the values as the timestamps in seconds.
4. Create a current_time segment with the following filters:
   • User Tag: current_time Time Elapsed Greater Than: 2 minutes
   • AND User Tag: current_time Time Elapsed Less Than: 5 minutes
5. Create a future_time segment with the following filters:
   • User Tag: future_time Time Elapsed Greater Than: -5 minutes
   • AND User Tag: future_time Time Elapsed Less Than: -2 minutes

• Enter the current_time segment 2 minutes after the current time date and exit the segment 5 minutes after the current time date.
• Enter the future_time segment 5 minutes before the future time date and exit the segment 2 minutes before the future time date.