The phrase "a time when rules" is correct and usable in written English.
It can be used to refer to a specific period or situation characterized by certain regulations or guidelines.
Example: "Reflecting on a time when rules were strictly enforced, we can see how it shaped our current practices."
Alternatives: "an era of regulations" or "a period of guidelines".
In a time when cynicism rules, her eager humanity is ever more precious.
That led to a long debate about how to account for the envelopes.It is particularly unfortunate that the FEC is getting bogged down in such debates at a time when the rules about campaign finance are in flux.
They recall Mr Clinton's presidency as a time when the rules on Wall Street banks were loosened, in their view setting the scene for the later financial crash.
At a time when buffoonery rules the White House, I find it a relief to watch Colbert turn the day's disasters into hilarious jabs, providing me with a little joy before I go to bed.
The titanic shocks that these paradoxical pieces delivered were achieved by a man who worshipped the gods of musical conservatism at a time when the rules of composition were being dismantled by the likes of Gustav Mahler and Richard Strauss.
I think it's also important to recognize that Manara began his artistic career at a time when the rules were changing, both in Italian society and in Italian comics.
But he served at a time when Democrats ruled Texas.
"Once upon a time, when hippies ruled the earth, you wanted to avoid looking too slick," Mr. Mathews said.
To a story he devised with the playwright Randy Weiner, Mr. Pinsky set his libretto in a time when robots rule the earth.
It was a time when Bonapartism — rule by generals — was a living threat, most notably in the cult of Georges Boulanger, the general who nearly pulled off what would have amounted to a coup d'état, in the late eighteen-eighties.
