Following new filters have been added to the content delivery api:

• first_published_at_gt After a specific first published date (Format: 2018-03-03 10:00)
• first_published_at_lt Before a specific first published date (Format: 2018-03-03 10:00)
• published_at_gt After a specific published date (Format: 2018-03-03 10:00)
• published_at_lt Before a specific published date (Format: 2018-03-03 10:00)

Use cases:

You could for example do delta updates by getting content items with the published_at_gt parameter or search for content items that have been published in a specific month by using a combination of the first_published_at_lt and first_published_at_gt filter.