Question:  Can a fundraiser for a charity be permitted outside of the agency's six-week Combined Federal Campaign (CFC) period?

Yes, but there are few authorized exceptions outside the established annual time frame which is
September 1 through December 15. Upon written request, the Director of the Office of Personnel Management may grant permission for solicitations of Federal employees, outside the CFC, in support of victims in cases of emergencies and disasters. These emergencies and disasters are defined by the Federal Emergency Management Agency (FEMA).

In addition, OPM has determined that child-care centers located at Federal installations may conduct special solicitations under the policies and procedures approved by the head of the agency sponsoring the child care center. However, OPM requires that such solicitations not be conducted during the annual CFC campaign periods and comply with standards of conduct and restrictions set by the Office of Government Ethics regarding fundraising from prohibited sources and subordinates as well as collective bargaining and partnering obligations.

Regulations governing CFC can be found at: http://www.opm.gov/cfc/html/regs.htm