[R] Convert character date time to R date-time variable.

[Sorkin, John]

Colleagues,

I have a matrix of character data that represents date and time. The format of each element of the matrix is 
"2020-09-17_00:00:00"
How can I convert the elements into a valid R date-time constant?

Thank you,
John



John David Sorkin M.D., Ph.D.
Professor of Medicine, University of Maryland School of Medicine;

Associate Director for Biostatistics and Informatics, Baltimore VA Medical Center Geriatrics Research, Education, and Clinical Center; 

PI Biostatistics and Informatics Core, University of Maryland School of Medicine Claude D. Pepper Older Americans Independence Center;

Senior Statistician University of Maryland Center for Vascular Research;

Division of Gerontology and Paliative Care,
10 North Greene Street
GRECC (BT/18/GR)
Baltimore, MD 21201-1524
Cell phone 443-418-5382