The phrase "after a month when" is not correct and sounds awkward in written English.
It may be intended to refer to a specific time frame following a month, but the construction is unclear and lacks proper context.
Example: "After a month when we had no communication, I decided to reach out."
Alternatives: "after a month during which" or "after a month that".
After a month, when it became clear that he was adamant, he was released.
"People could have been returning after a month, when the iodine had disappeared," he says now.
After a month, when no new Petscop videos had materialized, a sense of confusion and despair took hold.
After a month when it appeared the Islanders would never stumble, they have lost two in a row and three of their last five.
The hotel pays 50 cents a piece for them getting them at the age of a week or so and replacing them after a month, when they get into the ugly duckling stage, with a new bunch of youngsters.
They handed it in to Lancashire Police who said they returned the cash to the pair after a month "when no criminal activity relating to it came to light".
Cordoba died after about a month when he couldn't eat the raw fish and turtles, Alvarenga has said.
After about a month, when it was discovered that he was an Iraqi, the CIA's legal advisers decided that he had to be detained in Iraq.
But he surprised his physical therapists after about a month, when he began using crutches and a straight brace on his leg.
José Blanco, one of Mr. Zapatero's senior ministers and the government spokesman, said that the inclusion of a "principle of budget stability" in the constitution should help Spain confront further market pressure, after an August when investors raised the country's borrowing costs close to record highs.
There is just rubbing your face so that the dirt comes off in needle-thin rolls of black dust mixed with old sweat, and the smell is the settled smell when you have been through dirty and come out the other side — a week after, a month after — when you are no longer rank, just stale.
