Mauro Cristofani, Helmut Rix and others claim that there is a word celutule on the tablet known as the Tabula Capuana. Such a word would be a hapax if it weren't for the analysis that this item is composed of celu plus a declined deictic -(i)tule. According to the Celtiberia website, Cristofani is cited for a translation of celutule apirase as "nel giorno celuta nel mese apire" ("in the day celuta of the month apire"). Yet another swiss-cheese translation attempt. Yawn. It ignores the patterns within the rest of the text of this interesting artifact.
The analysis of celutule as celu plus a declined deictic form of -ta "the" is unlikely here thanks to the fact that we already have ital attested in line 10. If we acknowledge -a- not -u- in ital (which is undoubtedly the demonstrative ita "that" declined with a genitive case ending -l) then unless one wants to push an assumptive claim that there was phonetic or spelling variation within the same text, this little hypothesis is already a goner.
What I don't understand is why people so often fail to pay attention to the entire text before making their piecemeal translations of specific lines. This text in particular is written in continuous fashion without spacing or dots to indicate the division of one word from the next. We only have dots placed next to the coda consonant of a syllable, as is the Old Etruscan fashion of writing. So knowing this, we can all see how the possibility for missegmentation of these words is immense unless we take into account other dependable cues, such as the comparison of different lines or words within the same text. At line 9 and between lines 10 and 11, for example, Rix presents an unusually long word that is surely an undivided clump of a few words that he had avoided to seperate for some mysterious reason: riθnaitultei. The only sensible division of this lexical mass is riθnai tul tei. We can be assured of this division because these words are found in various combinations in the same artifact, for one thing. The word tei is found in line 4 according to Rix and is already known from other artifacts to be the locative form of ta "that". We also curiously find far too many words with tul in them together in this same artifact: apertule, celutule, isveitule, riθnaitultei, tiniantule, mavilutule and macvilutule. Really? C'mon, people. Unlike the Liber Linteus, where we find for example both postfixed accusative article -cn and -tn, we are supposed to believe that the Tabula Capuana shows a different grammatical pattern that has an odd bias towards the l-genitive of ta rather than ca.
It seems as though experts almost went out of their way on this one to overuse the one example of -itula in ET OA 4.1 (mi selvansl smucinθiunaitula, showing an unexplained epithet of the god Selvans divorced from credible historical connection) as a pretext for loose theories about Etruscan calendars or other causes.
If the current view were working however, the text of the Tabula Capuana and other texts of similar length would be completely solved by now with detailed commentaries on the history and contemporary context of these rites in the surrounding ancient world. So far, we have nothing of the sort. Only piecemeal translations. And in all of this, I can't figure out for the life of me why the more obvious solution of reading tul "boundary marker", as found throughout the Liber Linteus (LL 2.iii, 2.xv, 3.xxii, 4.xii, 4.xiii, 4.xvi, 5.v, 5.ix, 5.xii, 9.iv, 9.xvi, 9.xviii, 9.xx, 10.ii and 11.xix), isn't explored by these authors.
 Cristofani, Etruschi: una nuova immagine (2004), p.218 (see link). Rix, Etruskische Texte: Editio Minor, Band II (1991), p.9 (see link).