The phrase "longer deadline" is correct and usable in written English.
It is often used when extra time is needed to complete something, for example, "We have been granted a longer deadline to finish the project."
Ms. Wolfe said a fairer proposal would give small towns a longer deadline to process the applications.
Results showed that participants who faced the longer deadline wrote longer responses to the survey and spent more time on it.
But sometimes a longer deadline is necessary if a task is inherently more complex or there are outside factors that are going to add time to the schedule.
In another study, a longer deadline led respondents to commit more money to filing their tax returns, even though the length of the deadline arose from an incidental factor — the arrival of a lost W-2 tax form.
On Sunday, Democrats familiar with the talks said Reid was pressing McConnell to accept a quicker deadline on a temporary measure to fund federal agencies and reopen the government and a longer deadline for raising the debt limit.
We studied this by offering college students three Hershey's Kisses to complete an assignment with a quick deadline, or five Hershey's Kisses to complete a similar assignment with a longer deadline.
First, whereas Parkinson's law suggests that longer deadlines lead people to set easier goals and therefore decrease effort, we found that longer deadlines increase an assignment's perceived difficulty.
At first, Mr. Mayor thought he could change that, negotiating with buyers for longer deadlines to avoid excessive overtime, according to people who worked with him.
We concluded that when faced with multiple deadlines for tasks that vary in importance, people regularly pursue less-important assignments with shorter deadlines than more-important assignments with longer deadlines.
And there are times when longer deadlines are more effective than short deadlines, such as when individuals have a natural tendency to under-plan, in saving for college or planning for retirement, for example.
They were also hard to read, and invariably out of date, because the I.R.S. gives companies much longer deadlines to file pension information than it gives for tax returns.
