expression
today of all days
Expresses frustration or irony that something (usually bad) happens on this particular day, when it could have been any other day. Often used with negative events or complaints.
よりによって今日、電車が遅れるなんて。
Of all days, the train is late today.
よりによって今日、雨が降るとは思わなかった。
I didn't expect it to rain today, of all days.