をもって — how do you tell the "means" reading from the "time" reading?

Question

Studying for N1 this July and をもって keeps showing up in two different flavors. In 誠実さをもって人々に信頼されています it clearly means "through/by means of sincerity," but I've also seen it used to mark a specific date/time, like closing notices. Is there a reliable way to tell which sense is intended, or is it purely contextual?

Accepted Answer

Mostly contextual, but there's a strong pattern: when をもって follows an abstract quality, skill, or method (誠実さ, 実力, 書面 "in writing", etc.), it's the "means/by means of" sense — translate as "with" or "by." When it follows a date, time expression, or something like 本日 ("today") / 以上 ("the above"), it's marking a point in time or a formal cutoff — translate as "as of" or "at." You'll see this time-marking sense a lot in formal announcements, e.g. 本日をもって営業を終了します ("as of today, we are closing the business").

Answer

Adding on — the fact set's own example この賞をもって、彼女の努力が認められました sits right at the boundary: the award itself is being treated almost like the "means" by which recognition happened, so it leans toward the means/method reading even though an award could feel event-like. If in doubt, ask whether the noun is a quality/instrument (means) or a date/formal marker (time) — that split covers the vast majority of cases.