Requests for an activity adjustment to be approved must be made by 1st December in the first year of teaching, so Y12 for A level (Section 1e of the Guide to NEA). These can only be applied for with disabled candidates. All other activities are as per the DFE list.
The visit arrangement form must be completed by 14th January. See Appendix A of the guide to NEA
You can view the non-exam assessment timelines for AS/A Level here.
Entries must be made by 21st February in the year of assessment.
All NEA marks for all practical activities and the tasks need to be submitted to OCR by 31st March. This is a requirement of the qualification. There are no seasonal activities anymore and as such no seasonal dates for submission. See Appendix B of the guide to NEA, also section 3c.2 of the AS/A level guide to NEA.