Hello okabe.yasufumi,
From our documentation here: Apryse WebViewer Class: Annotation, the ‘DateModified’ attribute gets set whenever an annotation is modified. It will be changed automatically if you make any changes to the annotations like moving them around or manipulating them. You can access it using something like: annotations[0].DateModified as shown below:
I see that your document’s annotations are locked. Changing the ‘Locked’ status could change the DateModified. Perhaps that is what is happening here to give them all the same DateModified?
Best Regards,
Carlo Mendoza
Web Developer
Apryse