Most teachers of Latin would doubtless cross out ubi if used by a pupil in the sense of ‘When?’ and substitute for it the other interogative adverb quando, notwithstanding the entry ‘quandō, ubi, when?’ retained from the older editions in Prof. J. F. Mountford's revision of the Revised Latin Primer (§ 168) and added in his revision of ‘Bradley's Arnold’ Latin Prose Composition (§ 157 (ii))— entries which are paralleled in some quite elementary Latin text-books.
No other authoritative Latin grammar, and no dictionary, that I have been able to consult records an interrogative use of the temporal ubi, but when the matter was brought to his notice Prof. Mountford instanced, from Merguet's Lexicon, the following passages of Cicero, which at first sight certainly seem to justify the entries:
de demo 77: ‘quamquam ubi tu te popularem, nisi cum pro populo fecisti, potes dicere?’
82: ‘ubi enim tuleras ut mihi aqua et igni interdiceretur?’
127: ‘ubi te isti rei populus Romanus praefecerat?’
pro Cael. 15: ‘ubi denique est in ista suspicione Caeli nomen auditum?’
When it was pointed out that all these passages, even though their natural translation undoubtedly appeared to be ‘When…?’, were rhetorical questions, not genuine requests for information like quando Roman uenisti?, and that they certainly did not prove that ubi and quando were generally interchangeable, Prof. Mountford replied:
‘…The first striking fact is that in all the speeches and philosophical works of Cicero, the only other possible examples are:
de domo 128: “sed quaero quae lex lata sit ut tu aedis meas consecrares, ubi tibi haec potestas data sit, quo iure feceris”.