Purchase date of an asset for the purposes of capital gain reporting

I have recently sold some my holdings in a unit trust which were not bought all at once, i.e. made several investments in the same unit trust over the years. To compound the problem I inherited some units from my late husband. Which date should I use as a purchase date if not only one date?

Hi,
This may be similar to a S104 holding, please see guidance at:
Shares and Capital Gains Tax (Self Assessment helpsheet HS284)
Thank you.