に限って: precisely the wrong occasion or trust in one person
Read an unexpected event on a particular occasion and a strong belief about a particular person. Explore the speaker's stance in context alongside the restrictions of formal に限り notices.
Trouble precisely when it matters
急いでいる日に限って、電車が遅れます。 complains that trains run late precisely on days when the speaker is in a hurry. It highlights those occasions rather than proving statistically that delays never occur on other days.
傘を持っていない日に限って、雨が降りました。 means that it rained on the very day the speaker had no umbrella. 持っていない modifies 日 as that day's state; the following clause places the rain in the past.
Believing that this person would not do it
彼に限って、約束を忘れることはないと思います。 means that the speaker believes he, of all people, would not forget a promise. The focus is the speaker's trust, not a test result measuring his memory.
This use follows the singled-out person with a negative judgment. Interpret the same に限って differently depending on whether a time noun leads to an unexpected event or a person leads to a prediction that something will not happen.
Restrictions in notices and the speaker's reaction
本日に限り、入場無料です。 announces free admission for today only. 本日に限って can also mark a restriction, so do not always translate に限って as an unfortunate coincidence; check the result and tone.
大事な日に限って失敗しました。 expresses disappointment about failing on an important day. It is not a rule specifying days on which failure is permitted, so distinguish a formal restriction from the speaker's evaluation.
Quick check: Does あの人に限って、うそは言わないでしょう。 objectively guarantee that the person will not lie?
Show the answer and why
No. It expresses the speaker's strong trust and expectation that this person would not lie. The grammatical expression itself does not guarantee the facts.