I found this part of the judgement in the Mirror case where the judge dismisses the cases of 2 of the claimants as out of time
This seems to be the relevant bit of the judgement
The relevant limitation issue in both cases was whether they could have realised, by exercising reasonable diligence, that they had a worthwhile claim against Mirror Group by a date 6 years before they issued their claims – so by 7 December 2014 in Mr Sanderson’s case and by 30 July 2015
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Mirror Group’s Limitation Defence. Ms Sanderson’s claim was issued on 7 December 2020; Ms Wightman’s on 30 July 2021. The relevant limitation issue in both cases was whether they could have realised, by exercising reasonable diligence, that they had a worthwhile claim against Mirror Group by a date 6 years before they issued their claims – so by 7 December 2014 in Mr Sanderson’s case and by 30 July 2015 in Ms Wightman’s case. I have explained in my judgment how the legal test applies in the cases of individual claimants who complain about the underlying unlawful information gathering lying behind published articles. An important question is the extent to which any claimant was misled by the terms of the articles, or by what Mirror Group was saying, into believing that a friend or family member had leaked their private information to the Press. That could be material because it might lead a claimant not to pay attention to news coverage relating to phone hacking, which they might have done if they had not been misled. However, in both Ms Sanderson’s and Ms Wightman’s cases, I have found that they were not misled in that way.
The question is therefore whether each of them could have realised much earlier, by the relevant dates in 2014 and 2015, that they had a worthwhile claim against Mirror Group. In their cases, that turned on whether, by being reasonably attentive to the news and social media from 2012 to 2015, they would have been alerted to a possible claim that they should investigate further. I have concluded in both their cases that if they had been reasonably attentive, they would have been alerted to a possible claim, and so they could reasonably have found out by the end of October 2014 that they had a worthwhile claim against Mirror Group. Accordingly, time for their claims expired six years after that date. Both claims are therefore barred by the Limitation Act and must be dismissed.
https://www.judiciary.uk/wp-content/uploads/2023/12/Duke-of-Sussex-v-MGN-Judgment-Press-Summary.pdf