What does the clock symbol mean on the ordinance info?
Why do they expire and why is there a difference in how long before they expire?
The 90-day expiry ordinances are ones that were originally shared with the temple, then later were reserved by a person. This was introduced so that if a relative found that the ordinances had been shared with the temple but wanted to do them personally, they would be able to do so. The 90 day limit was imposed so that if the person subsequently forgot that they had reserved them or had not had time do them, after 90 days they would automatically be returned to the temple.