Looking at scanner.log, the following lines appear:

[18:10:16.7249] Slim::Schema::wipeDB (302) Start schema_clear
...lots of stuff...
[19:13:53.0836] Slim::Music::Import::runScanPostProcessing (372) Finished background scanning.

This should give a total scan time of 01:03:36.3587 (if my time arithmetic is correct).

This is what gets shown on the scanner progress page at the end of the scan:

============================================================================
This page shows the progress of each phase of the scanning process.
Directory Scan (2399 of 2399) Complete 00:57:22

Playlist Scan (20 of 20) Complete 00:00:03

Merge Various Artists (1772 of 1772) Complete 00:02:11

Artwork Scan (1772 of 1772) Complete 00:02:23

Database Optimize ( of ) Complete 00:01:36

SlimServer has finished scanning your music collection.Total Time:01:62:-3505
=============================================================================

So...just a friendly reminder:

hours   = int( elapsed_seconds / 3600 )
minutes = int( (elapsed_seconds - (hours * 3600)) / 60 )
seconds = elapsed_seconds - ((hours * 3600) + (minutes * 60))

or, if you'd rather:

hours   = int( elapsed_seconds / 3600 )
minutes = int((mod((elapsed_seconds/3600),1)*3600)/60)
seconds = mod(((mod((elapsed_seconds/3600),1)*3600)/60),1)*60