There is a large c-shaped mark at the left which we take to be the left-hand side of a large v at the beginning of line 2; for the enlarged initial digit cf. 291.i.3.
There is a space between c and the edge of the leaf which suggests that the month-name is probably abbreviated here, as it probably also is in line 6. This cannot be proved in any of the other entries since the writing runs up to the edge of the leaf, but it is possible that the month-name was abbreviated in every case; February is often abbreviated as Febr (see TLL VI.1 412).
See note to line 3.
Idus: the writing is very abraded here but the order of dates means that this is the only possible reading.
The final trace looks most like m, i.e. M[aias, but we cannot exclude a (A[priles).