Retrospective employment contract?

[Willhire89]

Senior employee of small limited company I now find was never given a contract when he started in April 2011

Situation needs to be regularised - standard company contract is available but is it best to date it April 2011 so all the wrongs are right and employee has the service ....or from now?

Employee is Ok with the April 2011 - starting from now kicks in a six month probation and still would leave the company in a retrospective breach.