Vacancy expiration mails sent too late

One-sentence description

The email for an vacancy expiration is sent after the expiration date.

Current behaviour

I received the following email on the 1st of march:

Hello!

A vacancy of Internship Capital Structuring, 'Rabobank' will expire within the next 30 days. Maybe you should contact them to negotiate a new deal.

Kisses,
The website

The vacancy "Internship Capital Structuring" has its expiration date set to 18-02-2018.

Expected behaviour

The email should have been sent on the 1st of February, not March.

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