Explore Data Avalability
I personally think that it really worht it explore your data avalability before any further analysis. It is very interesing to have a tool that can show you the data availability inside your folder tree. For this reason surfquake offers a command line tool that easily will show you a plot with lines where you have data, no data and gaps in red.
For big data, it can last a little bit but it shows you the progress on screen.
Command Line
Example
In the example, I simply navigate to the forder where I have placed three stations with three channels so nine files, then I run the command: