The
AIP says (page 6)
ATS: MON-FRI except HOL: SUM : 0600 - 2200 - WIN: 0700 - 2100.
i.e. no ATS (i.e. nobody in the tower) at weekends.
I have
departed from there at weekends and indeed it is silent and one has to remain OCAS until able to pick up an IFR clearance from some enroute controller (Marseilles was the last one I was told to use, but they did not reply to the radio so I got another one). But I have never arrived there on a weekend.
It appears that there is no way to arrive "IFR" at weekends and indeed that would definitely be the case in the UK, but I read something about France allowing IAPs without ATC, using pilot calls only.
A more regular way would be the US system whereby a remotely located approach controller clears you for the IAP but I cannot find any evidence of that in this case.
I cancelled that trip anyway due to bad wx all around but not being able to land at LFLN on Sunday would have really been the icing on the cake....