| 摘要 |
PROBLEM TO BE SOLVED: To accurately activate a telephone set, even when operation time is switched, based on an operating time switching system. SOLUTION: In the case of switching a standard time period and a DST (daylight saving time) period in the operating time switching system, a switching discrimination section 14B discriminates the propriety of switching and an operating time of its own telephone set, an operation time management section 14A selects the standard time or the shift time, corresponding to a new period after the switching based on a switching available discrimination function from this switching discriminating section 14B for an operating time. |
