From the Airtours on-line brochure....
- DJE shows with airline code BJ
(Nouvelair I think...)
Flight timings are shown as:
Those flight timings are the same as the MYT operated NCL
flights... and as the DJE flights are being flown by a Tunisian airline you'd expect the return time to be earlier than the departure (unless they were on some sort of W pattern which is very unlikely)
Likewise, the LGW
flights to DJE are also copies of the MIR
I would think that at this stage, Airtours haven't confirmed either airline or flight times for the Djerba flights...
This is further confirmed if you try checking availability on holidays to the Djerba area on the Airtours website where the departure date is shown as Saturday
and both carrier and timings are shown as 'TBA'.
I don't like signatures...