(3) Days, unless otherwise defined or limited, means calendar days and not workdays. In computing a period of time prescribed in this chapter, the day of the action or event after which the designated period of time begins to run is not to be included. The last day of the period so computed is to be included unless it is a Saturday, a Sunday, or a legal holiday in which event the period runs until the end of the next day which is neither a Saturday, a Sunday, nor a legal holiday.
5 CFR § 210.102
The definitions in paragraph (b) of this section apply throughout this chapter, except when a defined term is specifically modified in or specifically defined for the purpose of a particular part.