S3 Glacier Instant Retrieval pricing details

Hello,

From the S3 FAQs:

• S3 Glacier Instant Retrieval is designed for long-lived, rarely accessed data that is retained for months or years. Objects that are archived to S3 Glacier Instant Retrieval have a minimum of 90 days of storage, and objects deleted, overwritten, or transitioned before 90 days incur a pro-rated charge equal to the storage charge for the remaining days.
• Objects that are archived to S3 Glacier Deep Archive have a minimum of 180 days of storage. If an object is deleted, overwritten, or transitioned before 180 days, a pro-rated charge equal to the storage charge for the remaining days will be incurred.

So, my understanding is that if you place an object in S3 Glacier Instant Retrieval during only 30 days and you transition it to another tier before the 90 days, you will be charged for the additional 90 - 30 = 60 days of S3 Glacier Instant Retrieval in addition to the cost of S3 Glacier Deep Archive in which the object will reside.