If you would like to set up a one-time cronjob, i.e. cronjob that runs at a specific time once and never repeats, you can follow these instructions:
- Click Add a cron job or Edit existing cronjob
- Enter URL to your cron script.
- Enter desired time into Time Pattern field, e.g. Feb 14, 2019, 7:30
- Make sure you select correct Timezone
- Click Save changes.
And that's it. You can click on the time pattern field e.g. Feb 14, 2019, 7:30 in the example above, and it'll show the next execution time so you can confirm the time settings are correct.