Via Properties - Attributes menu I can change files' creation date and last modified date.
Files in Windows also have Access date - but there is no option in this menu for changing Access date.
Can you add this option in the future release of Opus?
Why do you want to change the accessed timestamp? It is largely meaningless/deprecated in modern versions of Windows.
(BTW, the Properties dialog is part of the Windows shell, not a part of Opus. Opus has other dialogs for setting timestamps, but even then it's unusual to do anything with the accessed timestamp as it's basically useless these days.)
Sometimes I need it in my work, when I have to update some reports that are supposed to be made several weeks or months ago. When I can't let some people know that these reports have been done recently. And if they see true access timestamp, this could lead to some unpleasant consequences.
Do you mean this software: Freeware – No Nonsense Software? Does it really work? It might have worked back in 2006 with WinXP, but it doesn't change the access timestamp on a Win10 system.
Repeating what Jon said: The accessed timestamp doesn't tell you when a file was last edited. It tells you when it was last opened. By anything. For any reason. To READ it or write to it. It could just mean something looked at it to index it, or get its icon, read some metadata, or it was opened to check the contents, to archive the file, or to sent it to someone as an attachment.
Opening the Properties dialog itself can bump the accessed timestamp!
It's so meaningless that newer versions of Windows don't even update it by default anymore in a lot of situations, as it just led to filesystem overhead and had no useful purpose.
This is why I asked why you needed to update it. The timestanp is so meaningless that I suspect most people wanting to use it have not understood what it does.