one fine day
Suddenly on some unspecified or unremarkable day. One fine day, the police showed up to tell me that my business partner had been using our company as a money-laundering service for nearly 10 years right under my nose. My father decided one fine day that he wanted to buy a camper van and travel the country on his own.
one fine day
at some unspecified or unknown time. 1990 Wilfred Sheed Essays in Disguise If Sydney blew away one fine day, Melbourne could easily take its place as a center of mateship and conspicuous democracy.