Yes the part of the sentence 'for whatever period' is correct and usable in written English.
It can be used when referring to any length of time, typically when making a general statement and not referring to a specific period of time. For example: "He worked hard for whatever period it took to achieve his goal."
If she is paid monthly then she needs to average her hours over a month, and if paid less frequently then for whatever period that is.
He added: "Comedy is a community, for whatever period of time, a half-hour of a television show or an hour in a club.
Properly funded and empowered for whatever period is necessary, working with full governmental co-operation, it could, in a much more cost-effective manner, deal with such cases.
"The tough part is that it just means you have to ride the roller coaster for whatever period is required," said one aide.
"We all recognize that regulation will be extended in some fashion for whatever period the elected officials wish to push it out for," said Joseph Strasburg, president of the Rent Stabilization Association, the city's largest landlord group.
"If public support is weak at the outset, U.S. leadership must be willing to invest the political capital to marshal support to sustain the effort for whatever period of time may be required," Mr. Rumsfeld wrote.
"Insofar as the Government are involved, obviously it's a difficult day for anyone to say I'm not going to have a job over whatever period".
I think the advice is always the same whatever period.
"We didn't attack too much in the first two periods and then in the third period, for whatever reason, it just kind of clicked in and we started attacking".
Subjects will be censored at any time when they stop taking the study drug for the treatment period, for whatever reason.
Heterosexuals who visited the community centers for whatever reason during the period of data collection were excluded from participation by staff and peers.
