Modifier 26 (Interpretation) DOS and POS

Regarding modifier 26, can someone please help me sort through the confusing info I've found and let me know the following:

Is the DOS the date the study was interpreted, or the date the study was done?

Is the POS the place of service the study was interpreted, or the place of service the study was done?

I need to attach modifier 26 to manometry (91010-26) and esophageal pH (91034-26) studies. Your help would be great appreciated. Thanks much in advance.

re: Modifier 26 (Interpretation) DOS and POS

DOS: The day the procedure was done.

POS: When the physician’s interpretation of a diagnostic test is billed separately from the
technical component, as identified by modifier -26, the interpreting physician (or his or
her billing agent) must report the address and ZIP code of the interpreting physician’s
location on the claim form.

See this article: https://www.cms.gov/Outreach-and-Education/Medicare-Learning-Network-MLN/MLNMattersArticles/Downloads/mm7631.pdf

re: Modifier 26 (Interpretation) DOS and POS

Thank you very much. I really appreciate the help.