I used to know a good bit about Excel, but that knowledge has slowly slipped away it seems. Any help is appreciated.

I've got Excel spreadsheets of the system log files from our telephone PBX system. I understand them, but they're rather incomprehensible to my co-workers in the row/column format they're in. So I need to display call data in a graphical format to show trends and patterns with calls. I've forgotten everything I might have known about graphs in Excel, and I had to do a Google search for "what is a pivot table", just to let you know where I am with this. (Last I used Excel it was version 2007. I've got Excel 2016 now.)

I'd like to end up with graphs that show what extensions were dialed, what calls went to voice mail, incoming and outgoing calls (and multiple calls by the same number), etc., but let me start out with some basic data. These are the times our phone system handled calls on a Sunday (we're closed Sundays, so this will be a small data set).

Time
8:24
9:52
10:08
10:29
10:36
10:47
11:36
11:59
13:27
14:33
15:09
17:13
19:17
19:26
19:35
20:42

At each one of those times a unique call came in to our system (I've already filtered for transfers to different extensions, transfers to voice mail, and similar which add their own time entries and seemingly create additional "calls" but are actually part of the same transaction - if that makes sense - there's another field in the data that links the parts of a call through the initiation through transfers to the end person hanging up the phone using a unique number). I've left off the rest of the data for now, such as the extension it went to, whether it was incoming or outgoing, how long the call was, and so on. I hope to one day understand how to represent all of that on a series of graphs.

How would I display this graphically? I'd like to show some type of range of when the calls came in. Whenever I try to make a graph with just this data, it pulls the row number of the entry into the chart as another list of values and ends up as nonsense on a graph. What format of graph would best show when the bulk of calls happen? Pie chart? Line graph? X/Y pattern thing? It's binary data - a call happened or it didn't, so I don't really have another data set I want to use with the times a call appeared in our system (until I understand this better).

I'm hoping this will click after my morning coffee, but I've been staring at this data all this week and I'm stuck. And embarrassed. Programming a PBX, no problem. Explaining it to humans...er, not so hot.

BPB