AppendDate

AppendDate is a straightforward piece of software that you can use to quickly append timestamps to files by opening their right-click menu. It doesn't include complicated options or configuration settings, making it accessible to all types of users.

Simple setup with context menu integration

The installation procedure is a speedy task that shouldn't impose any difficulties, thanks to the fact that there are no special options, prerequisite software products, or third-party offers involved.
Afterward, you're greeted by a small panel that gives you the possibility to define the preferred date format string. It's possible to add it to existing filenames as either a suffix or prefix. Apart from the fact that you can click a button to check for software updates, there are no other notable settings available.

Append timestamps to multiple filenames at once

From this point on, you can open the context menu of any selected file to seamlessly append the current date and time with one click, without any other confirmation messages.
This option isn't possible for folders, though. On the other hand, batch processing is supported by AppendDate, which means that you can append timestamps to multiple selected files at the same time to speed up the overall job.

Evaluation and conclusion

We haven't experienced any stability issues in our tests, since the app didn't hang, crash or show error dialogs. It left a small footprint on system resources, running on low CPU and RAM. Too bad that it hasn't received updates for a long time.
Although AppendDate doesn't have richer options and customization preferences, it offers a simple and effective solution for appending timestamps to multiple filenames at the same time. It's geared toward all types of users and it's free for non-commercial use.