Wrong lastModified timestamp after image rotate

[markg]

Steps to reproduce:
1. Open file (image) properties in Windows Explorer and record lastModified timestamp
2. Rotate this image in XnShell
3. Repeat step #1
Expected: lastModified should be time when the rotation was performed (current time)
Actually: remains unchanged
Environment: Windows 10, XnShell v4.16

I recorded lastModified timestamp before and after rotate with simplistic JUnit test in Java.

[xnview]

in options, "keep file date" is checked?