ADDITIONAL SYSTEM INFORMATION :
macOS 10.15.7
JDK 11.0.10
IntelliJ IDEA

A DESCRIPTION OF THE PROBLEM :
When running javadoc for a project, it still adds a timestamp to index.html of the generated JavaDocs. Here is an IntelliJ issue on the matter in which it was found that the issue occurs on 11.0.10 (and likely earlier iterations of Java 11) but not in Java 15: https://intellij-support.jetbrains.com/hc/en-us/requests/3131302?page=1

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Download https://jbs.zendesk.com/attachments/token/aLDXbXPZBck8UTc7aHhdnQ1O6/?name=JavadocTest.zip

2. Open project in IntelliJ IDEA Ultimate 2020.3.2.

3. Click the project root directory, and run Tools -> Generate Javadoc...

4. Run it with the options present in the following image (where the output directory can be changed if desired): https://i.imgur.com/8GArMuS.png

5. View index.html in the output directory, and see the timestamp

This result also occurs by running the javadoc command with the corresponding options on the command line.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
No timestamp would be generated in index.html.
ACTUAL -
A timestamp is generated in index.html.

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https://jbs.zendesk.com/attachments/token/aLDXbXPZBck8UTc7aHhdnQ1O6/?name=JavadocTest.zip
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FREQUENCY : always