The phrase "a month instead" is correct and usable in written English.
It can be used when suggesting an alternative time frame or duration in place of something else, typically in a comparative context.
Example: "I was planning to take a week off, but I think I might need a month instead to fully recharge."
Alternatives: "a month in place" or "a month rather".
In New York, Verizon recently sent letters to customers offering a calling plan that includes unlimited phone service for $35 a month, instead of $60, a 42percentt cut.
He paid women in prostitution for their services in a grace and favour flat in Dolphin Square for which he pays £1,000 a month instead of the going rate of nearly £3,000.
He said Mr. Papandreou also intended to introduce new rules to let companies reduce their work forces by 4 percent a month instead of the current 2 percent, and to increase taxes on fuel, tobacco and alcohol.
The basic AT&T plan — unlimited Internet and 450 minutes of calling — now costs $70 a month instead of $60 (plus taxes and fees), and comes with no text messages instead of 200.
For $9.99 a month, instead of taking why don't you give and take at the same time?
In a letter to health care providers sent Tuesday, Genzyme said adult patients would probably receive only one dose a month instead of the usual two, from October through January.
He goes to shopping malls less: once a month, instead of once a week.
And then, the landlord asked for $12,000 a month instead of $8,000, he said.
Other tactics have changed, too: children of any age, and sometimes adults, get the drops, and drives are held twice a month instead of every three months.
She said she was taking the drug as little as once a month, instead of every other day as she was supposed to.
To avoid arrests, the police worked with parents and decided the teenagers would be banned from the facility for a month instead.
