For Windows Users – Handy little trick with Notepad:

1) Type “.LOG” into a new Notepad document (without quotation marks). Note: It must be all UPPERCASE.

2) Save as a regular text document.

3) Close it.

4) Double-click on the doc. Every time you open the document it will show the time and date. You can just write any text below it. This is good for keeping a diary or for logging observations of something as it changes over time.