When you go to your loans feed, the OPDS includes availability information for each loan or hold. For a loan this means:

• The time the loan was created
• The time the loan expires

For a normal hold, this means:

• The time the hold was created
• The (estimated) time the book will be avilable
• Your current hold position
• The total number of holds

For a hold that's reservable, this means:

• The time the hold entered the "reservable" state
• The time the book will exit the "reservable" state

This information is rendered in a couple different places: in a clock icon that's part of the "Read" button or in a textual description on a book detail page.

Although the information is always present (when the circulation manager knows it), it's not displayed to the user in a consistent way. I know of two such problems:

1. Some views explain a hold solely in terms of your current position in the hold queue. Other views explain a hold solely in terms of the estimated time of availability. This may differ across platforms, but the main difference I'm thinking of is on Android, where a hold is described one way upon initial creation, and another way when you look at your loans feed.
2. On the iOS overview of current loans, the clock icon with time remaining is shown for ebooks (where the text is "Read") but not for audiobooks (where the text is "Listen").

It's likely that there are other inconsistencies rendering this information that I don't know about.