# US 8,542,557 B2 · Before/after specific weekday determination device, program media, method, daylight saving time determination device, and timepiece

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- Number: US 8,542,557 B2
- Document ID: US8542557B2
- Status: Granted
- Kind: B2
- Application number: 12/869,405
- Filed: 2010-08-26
- Published: 2011-03-03
- Granted: 2013-09-24
- Earliest claimed: 2009-08-28
- Assignees: Seiko Epson Corporation
- Applicants: Jaekwan Oh
- Inventors: Jaekwan Oh
- Web page: https://patentgrep.com/patent/US8542557B2

## CPC

- G04G 9/0076: {in which the time in another time-zone or in another city can be displayed at will}
- G04R 20/06: Decoding time data; Circuits therefor
- G04G: ELECTRONIC TIME-PIECES
- G04R: RADIO-CONTROLLED TIME-PIECES

## Abstract

A before/after specific weekday determination device that determines if an evaluation date is before or after a specific date that is identified as an n-th (where n is an integer of 1 or more) specific weekday from the beginning or the end of a specific month. The before/after specific weekday determination device is utilized in a daylight saving time determination device, and in a timepiece.

## Claims

### Claim 1

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.

### Claim 2 (depends on 1)

A timepiece comprising:
the daylight saving time determination device described in claim 1;
a timekeeping unit that keeps current time; and
a daylight saving time updating unit that adjusts the current time by the daylight saving time adjustment and updates to daylight saving time when the daylight saving time determination device determines that the current time is in a period when daylight saving time is in effect.

### Claim 3 (depends on 2)

The timepiece described in claim 2, further comprising:
a reception unit that can receive satellite signals transmitted from positioning information satellites and acquire positioning information and time information;
a time difference information storage unit that stores positioning information, time difference information for the positioning information, and daylight saving time pattern data corresponding to the positioning information; and
a time adjustment unit that obtains the time at the current location using positioning information and time information received by the reception unit, and information stored in the time difference information storage unit, and adjusts the current time kept by the timekeeping unit;
wherein the specific date data storage stores the start time, end time, daylight saving time adjustment, and apply conditions linked to the daylight saving time pattern data,
the time adjustment unit acquires time difference information for the positioning information from the time difference information storage unit, corrects the received time information by the time difference, acquires the time of the current location, and adjusts the current time kept by the timekeeping unit, and
the daylight saving time updating unit determines using the daylight saving time determination unit if the current time is in a period when daylight saving time is in effect based on the current time adjusted by the time adjustment unit, and the start time, end time, daylight saving time adjustment, and apply condition identified by the daylight saving time pattern data in the specific date data storage when daylight saving time pattern data is stored for the received positioning information, and updates the current time to daylight saving time if daylight saving time is determined to be in effect at the current time.