28päevane

28päevane is an Estonian compound adjective that means a duration of twenty-eight days or something that lasts for that period. It is used to describe a time span, cycle, or period in various practical contexts, such as scheduling, treatment plans, academic timetables, or project timelines.

In Estonian orthography, the form is typically written as a single word, 28päevane, and placed before the noun it describes. It functions as a pre-nominal modifier, similar to other numeral-based adjectives like kolmepäevane (three-day) or kahe nädalane (two-week). The exact noun it modifies determines the natural translations, for example: 28päevane ravikuur, a 28-day course of treatment; 28päevane eksamiperiood, a 28-day examination period; or 28päevane projekt, a 28-day project.

Common usage spans multiple domains. In medicine, 28päevane ravikuur specifies a treatment lasting four weeks. In education or research, it might describe a study or evaluation window. In business or project planning, it denotes a four-week timeframe for tasks or milestones. While the term is straightforward, it is more likely to appear in formal or technical writing than in casual speech.

Overall, 28päevane serves as a precise, compact way to express a four-week duration in Estonian, linking numerals with time-related adjectives to describe duration before a noun.