Here are the steps for overlaying the time axis in HOBOware:
Open HOBOWare
Open your first data file and choose plot; the data for this file will be displayed
From the top, click on the arrow tool, then bring the cursor to the bottom of the screen and double-click, and you will see a screen that reads Time Axis Properties; type a new name to create a new time axis - type over the original name to create a new series
From the same HOBOWare session, open your next file and select plot and your second file will be opened on the screen in a new tab
From the left side of the screen choose each series that you wish to merge, and at the top choose edit and then copy series
Click the tab from your original file and click on your graph and choose from the top edit; paste series onto the original file and you should see your series appear over the other date/time range
Repeat the process for each of the series you wish to copy from one data file to the next – you can create as many axis properties you wish to show