latest date to sell?

Happy New Year all,

I am in a nice position like most here to have a reasonable capital gain exposure to IRN that is 50% less on the 15th of April (12 mths holding). My question is, after I trawled through the annoucements, when is the final date to sell or should I wait till there is a compulsory aquistion. There seems to be no definitive dates as to when the offer expires that I can find.
However, after 2 weeks of festive activities and copious amounts of brain rotting alcohol, I may have overlooked them.
Can anyone supply the timeline, if there is one.

Thanks and cheers in advance.

P.