Hi,
After converting the file, only the latest date will be automatically saved. However, if you need to make any changes to the Metadata later, you can utilize PhotoPad Photo Editor. Simply upload the file, go to the Menu, select Tools, and then choose Edit Metadata. In this section, you will be able to set various information, such as the Date and Time, as per your requirements.
You can download the demo version from: https://www.nchsoftware.com/photoeditor/index.html