WhatsApp has started testing a feature that many of its users have wanted for years: the ability to schedule messages in advance. According to a report from WABetaInfo, the tool is now reaching a limited group of iPhone beta testers.

The move comes less than two weeks after scheduled messages made their first appearance in the Android beta. Earlier this year, WABetaInfo had spotted code references in a WhatsApp beta that pointed to the feature being developed, though it could not yet be tested at that point.

The timing highlights an odd gap for a service of WhatsApp's size. Meta does not usually publish user figures by platform, but Mark Zuckerberg said in April last year that WhatsApp had more than 3 billion monthly active users worldwide. Even with a reach that large, the app has lacked a scheduling option that rival platforms have offered for years.

As WABetaInfo describes it, the process starts in the chat window. After typing a message in the composer, a user taps and holds the send button, which opens a schedule screen with a date and time picker. A green button at the bottom confirms the choice and displays the exact delivery time beforehand. Once a message is scheduled, WhatsApp shows a confirmation in the chat that only the person who scheduled it can see.

There are limits on timing. Messages can be scheduled as little as 10 minutes ahead or up to two weeks ahead. Pending messages are listed in a dedicated section of the chat info screen, or the group info screen when the conversation is a group chat.

Group chats come with a notable rule. A scheduled message is delivered only to people who were already members when it was scheduled. Anyone who joins afterward will not receive it, even if they join before the message is actually sent.

The feature is not limited to text. According to the report, users can also schedule messages that contain photos, videos and links. One restriction applies for now: multiple photos or videos cannot be scheduled together, so each media item has to be scheduled separately.

As with most beta features, access is restricted to chosen testers, and there is no way to switch the feature on manually. WhatsApp has not said when scheduled messages will launch for everyone. With testing now underway on both iOS and Android, though, a broader release could arrive before long.