An SMS campaign in iSend can go out immediately or at a date and time you define, in the Greek time zone. Scheduling is enabled with a toggle on the campaign form, also accepts repetition daily, monthly or yearly, and the campaign can be paused or deleted until the sending time. From the API, scheduling is done with the schedule_time field in the send call.
How to set a sending time in the campaign
- Create the campaign as described in the article on the first campaign: name, sender, groups, message.
- Enable the Scheduling toggle.
- Set the date and time. The time is written in 24-hour format, for example 10:30.
- Check the time zone. The default is Europe/Athens. Change it only if the recipients are in another country.
- Under frequency leave "Once" for a simple send.
- Click Send. The campaign is saved as scheduled and appears in the list with its time.
At creation the platform checks that your balance is enough for all recipients. Credits are deducted at the time of sending. If in the meantime the balance drops because of other sends, the messages that are not covered appear in Reports as "Insufficient balance" and are not charged.
Recurring sends
Frequency accepts four options:
| Frequency | When it goes out | Example use |
|---|---|---|
| Once | On the date and time you set | Offer, announcement, invitation |
| Daily | Every day at the same time | Shift update, daily menu |
| Monthly | On the same day every month | Payment reminder, monthly update |
| Yearly | On the same date every year | Anniversary, annual renewal |
A recurring campaign sends each time to the contacts the group has at the moment of sending, so anyone added or removed in the meantime is taken into account. For reminders that depend on each contact's date, such as appointments, birthdays or expirations, automations are the right tool, not a recurring campaign.
Pausing, changing and deleting
Until the sending time, the scheduled campaign is yours to manage. From the Campaigns menu:
- Pause stops the campaign. It stays saved and does not go out until you resume it.
- Resume activates it again.
- Edit opens the form to change the text, groups or time.
- Delete removes it. There is no charge for a campaign that was not sent.
A campaign that has already started can be paused, but messages that have been delivered to the network cannot be recalled.
Which time to choose
For marketing messages, 10:00 to 20:00 on weekdays is the rule. Friday afternoon and Saturday morning work well for retail. Avoid the hours after 21:00 and before 09:00. For appointment reminders, the day before around 18:00 or the same morning two hours in advance. Order updates do not need scheduling, they go out the moment the status changes.
In the WooCommerce plugin, the abandoned cart module has its own quiet hours, so that a reminder that would fall at night goes out the next morning.
Scheduling through the API
In the send call, add the schedule_time field with the date and time in YYYY-MM-DD HH:MM format, in Greek time:
POST https://sms.isend.gr/api/http/sms/send
Authorization: Bearer YOUR_API_TOKEN
Content-Type: application/json
{
"recipient": "306912345678,306987654321",
"sender_id": "MyShop",
"message": "WE ARE EXPECTING YOU AT THE STORE TOMORROW AT 11:00.",
"schedule_time": "2026-10-20 10:30"
}
Without the field, the message goes out immediately. Seconds are ignored. Scheduled campaigns created from the API can also be viewed and managed from the platform, with the same pause and delete buttons. The remaining fields of the call are described in the article on the API key and the first SMS.
Frequently asked questions
Can I schedule a send for a few minutes from now?
Yes. Any future time is accepted, even a few minutes later. Always set a time after the current one. For an immediate send, leave scheduling disabled.
Is the time I set Greek time?
Yes, when the time zone is "Europe/Athens", which is the default. The switch between summer and winter time is applied automatically. If you change the zone for recipients abroad, the time you enter is interpreted in that zone.
What happens if I do not have enough credits at the sending time?
The messages that are not covered by the balance do not go out and appear in Reports as "Insufficient balance", without charge. Once you top up your credits, you send a new campaign only to those recipients. To avoid this, check the cost box before scheduling.