As can be seen from the screengrabs below the Demotix images were originally dated 25 August 2013 (top left corner of images, click to enlarge). At some point after the screen grabs were made, on 16 December 2013, Demotix amended the date to 26 August 2013.
The BBC’s varying responses to this matter are noted here.
Note, 18 November 2015: oddly, the Demotix images are currently once more dated 25 August 2013, as evidenced by this dated and timed screengrab.
Fabrication in BBC Panorama 'Saving Syria’s Children' 
Pingback: Fabrication in BBC Panorama’s ‘Saving Syria’s Children’ | Uprootedpalestinians's Blog
Pingback: Ex-Reuters freelancer, published in Mail and Telegraph, pictured with “Hell cannon” | Syria Solidarity Movement
Pingback: How the FSA/ISIS Fake Chemical Attacks to Force Regime Change | Friends of Syria