Calculate sum in View of ISO-style timestamps I have a text field on a node type, which the user fills out with a video duration in ISO format (no validation or anything). So, '4:33' or '04:33' would be likely values for this field. 

The client now needs a View which shows all these videos' titles and durations, and adds up the durations. I've looked at solutions like Views Calc and have had no real success. I've also have bad luck formatting the duration as  a datestamp and trying to manipulate it that way. I need a way to show something like this:


+----------+--------------+
|TITLE     | Duration     |
+----------+--------------+
|Swimming  | 4:33         |
|Diving    | 2:42         |
|Running   | 1:27         |
+----------+--------------+
|TOTAL     | 8:42         |
+----------+--------------+
Imho your two best bets would be to either create a custom formatter, or to use hook_field_attach_view_alter() to modify the display (this answer might help if you go down that road). I'd be happy to expand on either of those methods.

Is there any reason you're using a text field? I would've thought a dedicated duration field would've been the way to go. I've never used any myself, but Google suggests: HMS Field, Time Period. Have you had a look at them? They might already have a formatter that supports what you want (a longshot, perhaps!).