5 exercises — choose between by, until, within, in, and on for deadlines, SLAs, release windows, and recurring schedules.
0 / 5 completed
1 / 5
A ticket sets a firm deadline for a single point in time. Which sentence is correct? "Please merge the PR _____ Friday at the latest."
"By" for a deadline (no later than a point in time):By Friday means the action must be completed at or before that point — exactly what a deadline expresses. Until Friday would mean the action continues up to Friday, which is wrong for a one-off merge. Within Friday is not idiomatic for a single day. On Friday simply states the day without the "no later than" sense a deadline needs.
2 / 5
You want to say a feature freeze continues up to a release date. Which preposition is correct? "No new commits to the release branch are allowed _____ the release goes live."
"Until" for a continuous state up to a point:Until describes an action or state that continues right up to a moment and then stops — here the freeze lasts until release. By marks a deadline, not a duration, so by the release goes live is ungrammatical (it would need a noun, and the meaning would change). In and within express a period of time, not the "up to this point" relationship the sentence requires.
3 / 5
An SLA promises a maximum response window. Which sentence is correct? "The on-call engineer must acknowledge the incident _____ 15 minutes."
"Within" for a maximum duration:Within 15 minutes means at some point inside that window — the standard phrasing for SLA response times. By 15 minutes is not idiomatic because by takes a clock time or date (by 15:00), not a duration. Until 15 minutes wrongly implies continuing for that period. On is used with days and dates, not durations.
4 / 5
A roadmap describes a future timeframe. Which sentence is correct? "We plan to ship the v2 API _____ the next quarter."
"In" for longer periods (months, quarters, years): Use in with extended periods such as quarters, months, seasons, and years: in the next quarter, in March, in 2026. On is reserved for days and dates (on Monday, on 3 March). At is for precise clock times and certain fixed expressions (at 09:00, at midnight). By would change the meaning to a deadline rather than a timeframe in which the work happens.
5 / 5
A standup schedule fixes a recurring meeting on a specific day. Which sentence is correct? "The sprint retrospective takes place _____ the last Friday of every sprint."
"On" for specific days and dates: Use on with named days and calendar dates: on the last Friday, on 30 June, on Tuesdays. In is for longer periods (months, years). At is for clock times (at 16:00). Within expresses a duration window, not a fixed day. A reliable rule of thumb: at a time, on a day, in a longer period.