Nominatim update.php running but 'Data last updated' timestamp remains the same

I have freshly installed Nominatim on a brand new server and went through all the instructions to import the full planet osm data. All worked well and I have a Nominatim installation working now, capable of doing search and reverse search. I downloaded the full planet file on the 5th of March 2017, and it took a bit less than a couple of weeks to index, and now it is running fine. The home page displays:

Data last updated: 2017/02/28 23:58GMT.

I suppose this is the date the OSM file was generated.

I have now tried to set up the updater and after installing osmosis I updated the settings in local.php as follows:

@define('CONST_Osmosis_Binary', '/usr/bin/osmosis');    
@define('CONST_Replication_Url', 'http://planet.openstreetmap.org/replication/day');
@define('CONST_Replication_MaxInterval', '3600');
@define('CONST_Replication_Update_Interval', '60');  // How often upstream publishes diffs
@define('CONST_Replication_Recheck_Interval', '60'); // How long to sleep if no update found yet

I changed to use day replication because I wanted to recover 3 weeks of updates or so, and updating every day is enough for me. Then I did:

./utils/setup.php --osmosis-init
./utils/setup.php --create-functions --enable-diff-updates

And finally ran this:

nohup ./utils/update.php --import-osmosis-all &

It seemed to be doing a lot of stuff and took quite a number of hours to stop outputing logs. It seems to be running periodically too.

However, Nominatim's web page is still showing that the Data last updated: 2017/02/28 23:58GMT.

How to I check if osmosis is really updating correctly?

My configuration.txt has the following:

# The URL of the directory containing change files.
baseUrl=http://planet.openstreetmap.org/replication/day

# Defines the maximum time interval in seconds to download in a single invocation.
# Setting to 0 disables this feature.
maxInterval = 3600

I have this in my state.txt:

#Wed Mar 29 20:46:08 CEST 2017
sequenceNumber=1659
timestamp=2017-03-29T00\:00\:00Z

I've tried to change the maxInterval to 0, in case that was affecting it. Did it 4 hours ago, but still the data last updated time is the same.

The output of update.php is showing lines like:

  Done 75495 in 11397 @ 6.624112 per second - Rank 26 ETA (seconds): 17284.882812
  Done 75498 in 11398 @ 6.623794 per second - Rank 26 ETA (seconds): 17285.261719
  Done 75506 in 11398 @ 6.624496 per second - Rank 26 ETA (seconds): 17282.222656
  Done 75515 in 11399 @ 6.624704 per second - Rank 26 ETA (seconds): 17280.320312

What could be the reason the data is not updating properly?