Before/after specific weekday determination device, program media, method, daylight saving time determination device, and timepiece

A daylight saving time determination device, comprising:

• an evaluation date input unit that inputs a number M1, a number D1, DW1, and Hm1, where M1 denotes the month of the evaluation date, D1 denotes the day of the evaluation date, DW1 denotes the weekday of the of D1, and Hm1 denotes the hour and minute of an evaluation time of D1;
• a specific date data storage that stores a number M0, DW0, a number DS, a number DE, and Hm0, where M0 denotes the month of a specific date, DW0 denotes the weekday of the specific date, DS denotes a first candidate date of seven candidate dates that could be the specific date in M0, DE denotes an end candidate date that is the last candidate date of the seven candidate dates, and Hm0 denotes the hour and minute of an evaluation time of the specific date, the specific date is a start time denoting the start date of daylight savings time and an end time that is the later than the start time and denotes the end date of daylight savings time, the specific date data storage further storing a daylight saving time adjustment and an apply condition denoting if the period from the start time to the end time is when daylight saving time is in effect or not in effect;
• and
• a decision unit that compares the numbers input by the evaluation date input unit with the numbers stored in the specific date data storage and decides if the input evaluation date is before or after the specific date;
• wherein the decision unit determines that the evaluation date is before the specific date when (1) M1 is less than M0, (2) M1 is equal to M0 and D1 is less than DS, (3) M1 is equal to M0, D1 is greater than or equal to DS and less than or equal to DE, DW1 and DW0 are different, and the number of days Nd from DS to D1 is less than the number of weekdays Ndw from DW0 to DW1, or (4) M1 is equal to M0, D1 is greater than or equal to DS and less than or equal to DE, DW1 and DW0 are equal, and Hm1 is before Hm0;
• wherein the decision unit determines that the evaluation date is after the specific date when (5) M1 is greater than M0, (6) M1 is equal to M0 and D1 is greater than DE, (7) M1 is equal to M0, D1 is greater than or equal to DS and less than equal to DE, DW1 and DW0 are different, and the number of days Nd from DS to D1 is greater than or equal to the number of weekdays Ndw from DW0 to DW1, or (8) M1 is equal to M0, D1 is greater than or equal to DS and less than or equal to DE, DW1 and DW0 are equal, and Hm1 is after Hm1;
• and
• wherein the decision unit determines if the current time is before or after the start time using the current time as the evaluation date and the start time as the specific date,
• if, as a result of comparing the current time and the start time, the current time is determined to be after the start time, the decision unit determines if the current time is before or after the end time using the current time as the evaluation date and the end time as the specific date,
• if the current time is determined to be before the start time, or if the current time is determined to be after the end time, the decision unit determines that the current time is in the period when daylight saving time is in effect if the apply condition is that the period from the start time to the end time is when daylight saving time is not in effect, and
• if the current time is determined to be after the start time and the current time is determined to be before the end time, the decision unit determines that the current time is in the period when daylight saving time is in effect if the apply condition is that the period from the start time to the end time is when daylight saving time is in effect.