を通つうじてThroughout an entire period or range

How the whole-period meaning works

The noun before the expression names the full span being considered. What follows must apply across that span. This may be one continuing state, but it can also be an activity repeated at intervals; it does not have to be one uninterrupted event.

Continuous states and recurring activities

Natural range expressions

Typical nouns name years, seasons, lifetimes, academic terms, project periods, and other substantial spans. This construction is most useful when the writer wants readers to view the period as a whole, rather than merely state when one event happened.

Modifying a noun

を通つうじた and を通つうじての place the whole-period idea directly before a noun.

Whole period or intermediary?

For the whole-period meaning, を通つうじて and を通とおして overlap strongly. The target form is particularly comfortable in reports and formal descriptions, but there is no reliable rule that makes one form correct and the other incorrect in every whole-period sentence. Descriptions of their finer distribution vary, so learn the shared meaning first. A more important distinction is the noun before the expression: if it names a person, medium, tool, or experience that enables something, the phrase means “through” or “by means of,” not “throughout a span.”