how to record multiple important dates

[LauraPorturas]

Is there a best way/standardized way to record "emergence date" for reared organisms in Darwin Core?

Example of this type of specimen: a wasp and the gall it was reared from. The gall was collected on [eventDate], and several months later the wasp emerged from the gall.

What field would be best to record the second date associated with this specimen?

Thanks for any advice.

[dagendresen]

I would register one Occurrence (Event) for the "collected on" and another Occurrence (Event) for "emerged from the gall" - both with the same organismID (?).

[tucotuco]

There are various other ways to do it. The simplest is to include a comment in occurrenceRemarks field. The big disadvantage of that one is that it is likely to get lost among potentially many diverse comments in that field.

A second way is to add a dynamicProperty, which would look something like this:

{ "emergence date":"2021-08-06" }

That would be unambiguous as long as the user of the data understands what you mean by the key "emergence date".

A third way would be to add a MeasurementOrFact record in a separate file using the MeasurementOrFact Extension. In this case the extra file must have an occurrenceID field populated to match the occurrenceID in the record for the Occurrence for the collection of the wasp. The major advantage of this approach is that you can include lots of extra information about the measurement. The most important thing about this approach is to use a value for measurementType from a controlled vocabulary, if one exists.

[LauraPorturas]

Thank you both for your suggestions. I appreciate the advice.