What's the exact deadline for annual Retirement Annuity (RA) contributions?

I make annual lump sum contributions to my RA. In order for my annual lump sum contribution to qualify for tax deductions for the current year, do I only need to make the payment for my RA before the end of February, or does my financial advisor need to have allocated the funds to my RA before the deadline? i.e. Can I still make a contribution at 23:59:59 on 28 February 2017 which will count towards the 2016/2017 tax year?

Yes, you would need to have made payment by the end of today and have this allocated so that the fund will include the contribution in the current tax year.

Just to clarify, if my fund puts a cut off date of 24 February 2017-to have the contribution included in their current financial year- will I lose out on any tax benefits for the current year, if I only make payment on 28 February 2017?

I.e. It doesn't matter when I make the payment, but rather when my fund allocates the money paid?

The last payment date is decided by your fund