The printer’s manuscript has the normal until, but the 1830 edition has till. The 1908 RLDS edition restored until, in accord with the reading in 𝓟. The LDS text has maintained the 1830 till. Oliver Cowdery frequently spelled until as untill, especially in the original manuscript, where there are only a few examples of him spelling it as until:
until untill
extant cases in the original manuscript 6 31
in the printer’s manuscript 113 53
So it is quite possible that the 1830 till was the result of misreading untill in 𝓞 as till. Even so, there are no other examples of any mix-ups between until and till in the early transmission of the text. The only other case involves the 1840 edition, where until was replaced by till in Alma 19:16 (see under that passage for discussion).
Elsewhere in the text, in all other clauses referring to year(s), we have only until (13 times), never till, as in these five examples from 4 Nephi:
More generally, there are only seven examples in the original text of the conjunction till. But none of these refer to the passing of a specific time. For a list of those seven instances, see under Alma 19:16. Internal evidence suggests that the original text probably read until here in 4 Nephi 1:14.
Summary: Restore the use of until in 4 Nephi 1:14, which is consistent with all other uses in the Book of Mormon of until whenever we have the specification of a year.