The phrase "a certain time when" is correct and usable in written English.
It can be used to refer to a specific, but not precisely defined, moment in time.
Example: "There was a certain time when I believed anything was possible."
Alternatives: "a specific time when" or "an unspecified time when".
"There is a certain time when the emotions stop, and the professionalism begins," Ms. Womack said.
She has a certain time when she can go on Facebook; she can't go to sleepovers if we don't know her friend's parents".
But definitely an adult, and fixed in a certain time when adulthood was something to aspire to, not something to be avoided.
QUESTION FROM LUX: @Nick/Meghan — I also think there is a certain time when one is ready to read about grief.
There is also a certain time when noise is not allowed.
Moreover, the fact that an actuator is faulty is not detected when performing an action on it, as done in our approach, but after a certain time when the expected effect is not observed.
When a node fails and cannot be repaired within a certain time, or when the edge region nodes (or backbone nodes) roam to the outside of their adjacent field, the GMs will not be able to locate the roaming nodes in the AF by means of the mobile management model.
'There just is a certain time limit when things like lungs are formed.
In one new effort, in conjunction with a maker of mobile apps, Shopkick, viewers who open up an app at a certain time — say, when a store has a commercial running on a CW show — could receive special offers or discounts from that retailer.
It is shown that the maximum catalyst temperature an increase with time for a certain time period when the catalyst undergoes deactivation.
For this purpose, the standard deviation of differentials in a certain time interval when no event is taking place is taken as the noise level.
