To say "at a quarter to two," a Russian literally says "without a quarter two," where the preposition без means without and governs the genitive case. The word четверть means quarter and is a feminine third-declension noun which takes и in the genitive signular. When speaking of a quarter to one, they usually leave the number "one" out and simply say "hour." When speaking of the other "quarter tos," they usually leave out the word "hour."

For most time phrases, the way you say “It is now such-and-such o'clock” is different from the way you say “It happened at such-and-such o'clock.” When addressing times that are a quarter to the hour, however, the “what time is it” construction is the same as the “at what time” construction. Thus:

The time expression can also be used in the past and future tenses:

Since most other "at such-and-such a time" phrases start with the preposition в, it's a common mistake by beginning students of Russian to assume that the same holds true for times at a quarter to the hour. It does not. One never says in Russian «в без четверти семь»:

Other entries dealing with time are soon to come. Look for them under the categories "Time phrases" and "What time is it" and "At what time."