Invalid time in the Message sent by the Peer. Please ensure time synchronization between Netscaler and the Peer

I got this error while trying to connect to my Citrix gateway after an Azure AD authentication. The Netscaler were just provisioned on a SDX. The SDX was time sunchronize with my NTP server but something seems odd with this message :

Invalid time in the Message sent by the Peer. Please ensure time synchronization between Netscaler and the Peer

Checking the date on the first Netscaler gave me a totally wrong time.

Getting the current date and time :

date

and then to force a time synchronisation :

ntpdate

Everything should be back to normal and connexion is ok.