How different dates are related?

Date field	Description
Registration date	Date when a participant is registered to a collection protocol
Visit date	When a participant visits the clinic for specimen collection.
Collection Event date and time	The exact date and time when a specimen is collected from the participant in the clinic. This is applicable only to primary specimens. Child specimens don't have collected or received events.
Received Event date and time	The exact date and time when the specimen is received in the lab or biobank.
Created On date and time	The exact date and time when an aliquot or derivative is created. For child specimens, it's the processing date/time and for parent specimens, it's the collected date/time.
Creation Time	This is an audit date/time when the record was created. This is a standard field that is present in every object along with "Created by". At present, the object creation time and created by, update time and updated by is present only for 1. registration 2. visit 3. specimen
Update Time	This is an audit date/time for when the record was updated. This is a standard field that is present in every object along with "Updated by". At present, the object creation time and created by, update time and updated by is present only for 1. registration 2. visit 3. specimen
Processing Event date and time	The time when parent specimen is processed into derivatives/aliquots. The processing event is created on the parent specimen when you create derivatives or aliquots.

In case validations are to be added on any of the above timestamps, edit checks can be applied. Refer to Data Validation the wiki page for more information