Different times shown in logfile download vs logfile name - Bug or other???

#### Issue details
Hi,
Ive noticed that the logfile time shown in the download window (for downloading via mavlink) for specific files are different to the time that is used in the logfile name once the data has been downloaded.
As the logfile names on the SD cards are simple number, I believe this naming is occurring in the mission planner software.

Is this a bug? or something else?

The attached example shows:

Fetching log file 9/11/2017 10:34:02 AM...

and the file that was written is:

2017-11-09 10-22-11.log

I also think the file naming convention also changed between arducopter & arduplane... (different ordering of time & date if I recall correctly)...
May post this as a different issue.

#### Version
Mission Planner 1.3.52.0
ArduCopter 3.5.0-r08

#### Platform
[ ] All
[ ] AntennaTracker
[ X ] Copter
[ ] Plane
[ ] Rover
[ ] Sub

#### Airframe type
Quadcopter

#### Hardware type
Pixhawk

#### Logs
_Please provide a link to any relevant logs that show the issue_

Start by reproducing the discrepancy between the MAVLink download window timestamp and the downloaded logfile name described in the issue. Trace where each timestamp is obtained and written; done means the displayed and filename times use an understood, consistent convention, or the mismatch is documented as expected.

Written by the indexing model from the issue text.