How much is maximum value of og:ttl of facebook sharing?

Question

Context: Share a webpage on facebook wall of users

• Share a webpage with a image

• After some minutes, the image is deleted from my website

• About some days (7 or use og:ttl), the webpage is re-scraped. In the sharing post on facebook wall, the image is lost.

• Hope that the image of the sharing post will never be lost. Thus, og:ttl should be set very-large value.

At https://developers.facebook.com/docs/sharing/opengraph/object-properties?locale=en, og:ttl has minimum value 345600 seconds (4 days). But maximum value is not given.

1. How much is maximum allowed value of og:ttl of facebook sharing? Could I set very-large value (3153600000 ~ 100 years ~ forever) for the tag?

2. In case that the very-large value is allowed, Whether is the webpage still re-scraped but the time is not expired?

Answer 1

According to Facebook, the maximum og:ttl value is 2419200 seconds. That's equivalent to 28 days.

I came to this answer by setting my og:ttl to a very large number, then used the Facebook Debugger to scrape the page. The debugger returned an error: The og:ttl property must be an integer between 345600 and 2419200.