How do I make a variable date field fixed when saved as a new file?

I have made a journal template with a variable date field in the header so that each time I want to make a new journal entry, I open the template and the current date is automatically inserted. This is very handy and I like it. It saves me from having to look up the date and time. However, when I save this file and archive it, I don’t want the date to update each time the file is opened. How do I make the variable date fixed when saved as a new file without changing the template?

I am using Windows 8, 64 bit, libreoffice writer version,

You will have to change the template and replace the variable date field by the fixed date field. When creating a new document from the template the field will not keep the template date but lookup the current date. After that it will never change.