The phrase "a time when professional" is correct and usable in written English.
It can be used to refer to a specific period or moment in which professional activities or behaviors are relevant or being discussed.
Example: "I remember a time when professional standards were held in the highest regard in our industry."
Alternatives: "an era of professionalism" or "a period of professional conduct".
There was a time when professional athletes were depicted as the boys and girls next door.
But she came of age at a time when professional athletic opportunities for women were few.
The latest admissions come at a time when professional cycling has been shaken by a series of scandals.
Likewise important, he introduced a female actor in the leading role in his film Bhasmasur Mohini (1913) at a time when professional acting was taboo for women.
At a time when professional football, baseball and hockey players are eliminating war analogies in conversations, Hopkins refused to back away from his metaphor.
Mr. Gross, a former marketing executive at 20th Century Fox, started Movie Review Intelligence in 2009, at a time when professional film critics, threatened by layoffs and newspaper closings, were thought by some to be a vanishing breed.
So-called "conversion therapy" or "reparative therapy" began at a time when professionals in medicine and psychology considered homosexuality an illness that was amenable to treatment.
Even his small telescope could show up a great deal of detail on the moon's surface, making it especially attractive to amateur astronomers at a time when professionals tended to neglect it.
A time when professionals break away from their fifteen-hour workday to play dress-up, just like the characters they create and portray, and perform for the world.
Health professionals may have concerns about the very notion of self-management and its aim of encouraging patients' autonomy and control over their health and health care at a time when professionals are increasingly accountable for disease outcomes and adherence to evidence based guidelines.
The former first lady, a 1969 graduate of Wellesley College, studied law at Yale at roughly the time when professional schools, Ivy League universities, college sports and the military academies opened up to young women — not always with open arms.
