Method and apparatus for representing recurring events

• US 5,893,073 A
• Filed: 02/27/1995
• Issued: 04/06/1999
• Est. Priority Date: 02/27/1995
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation, Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: International Business Machines Corporation, Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Tso, Yvonne Yuen-Yee, Knutson, Martin Arthur, Dawson, Frank R., Kasso, Chris S.
• Primary Examiner(s): TKACS, STEPHEN R
• Application Number:
  US08/395,458
• Time in Patent Office: 1,499 Days
• Field of Search: 395/201, 395/207, 395/208, 364/705.07, 364/705.08, 368/1, 368/9, 368/10, 368/243, 368/244, 368/250, 368/251, 368/327, 705/1, 705/7, 705/8, 705/9, 705/11
• US Class Current: 705/7.12
• CPC Class Codes: G06F 40/123 Storage facilities
• CPC Class Codes: G06F 40/205 Parsing
• CPC Class Codes: G06F 40/289 Phrasal analysis, e.g. finite state techniques or chunking
• CPC Class Codes: G06Q 10/0631 Resource planning, allocation, distributing or scheduling for enterprises or organisations
• CPC Class Codes: G06Q 10/109 Time management, e.g. calendars, reminders, meetings or time accounting

Abstract

A method and apparatus for representing and storing the schedules of recurring events. The schedules are represented by recurrence rules generated according to a specific grammar. According to the grammar, each recurrence rule is composed of one or more recurrence commands. Each recurrence command corresponds to a cycle and includes a time interval indicator that specifies the duration of the cycle and a repeat quantity that determines the number of times the cycle is repeated in the schedule. Each recurrence command may also include an occurrence list that specifies at what times during a particular cycle the event occurs. The occurrence list may specify times in absolute or relative terms. Thus, the grammar supports recurrence rules for representing the schedule "first and tenth of every month" as well as the schedule "second Thursday and last Friday of every month". To represent schedules that terminate before the last event in the last cycle is completed, a symbol may be inserted into the occurrence list to distinguish the events that are performed on the last cycle from the events that are not performed on the last cycle. Complex schedules that involve cycles repeated within cycles are represented by multiple-command recurrence rules. The stored recurrence rules may be parsed to determine when events will occur. The grammar may be applied to a variety of applications, including calendar programs, video cassette recorders and home automation devices.

Claims

1. A method for representing a schedule of a recurring event in an electronic device, wherein the schedule includes one or more cycles, wherein each of said one or more cycles has a length, the method comprising causing the electronic device to perform the steps of:

a) for each cycle in said schedule, performing the steps of

a1) receiving a first input that specifies a unit of time used to measure the length of said cycle;

a2) receiving a second input that specifies a number of time units;

a3) generating a time-interval indicator representing the length of said cycle;

wherein said step of generating said time-interval indicator includes the steps of

generating a unit-type indicator corresponding to said unit of time;

generating a unit-frequency indicator corresponding to said number of time units;

a4) generating a repeat-quantity indicator representing how many times said cycle is repeated in said schedule;

a5) generating a recurrence command to represent said cycle, said recurrence command including said time-interval indicator and said repeat-quantity indicator; and

b) constructing a recurrence rule to represent said schedule, wherein said recurrence rule includes the recurrence command generated for each cycle of said one or more cycles.

2. The method of claim 1 further comprising the steps of:

invoking an operation at an initial occurrence time;

parsing said recurrence rule to determine subsequent occurrence times; and

invoking said operation at said subsequent occurrence times.

3. The method of claim 1 wherein:

said electronic device is a computer system;

said computer system includes a display device and a storage device;

the method includes the steps of

storing data representing said recurrence rule on said storage device; and

generating on said display device user interface controls for receiving said first input and said second input from a user.

4. The method of claim 3 wherein:

the method further comprises the steps of

executing a client application in said computer system;

executing a server application in said computer system;

said client application performs said step of generating on said display device user interface controls;

said client application performs said step of receiving said first input;

said client application performs said step of receiving said second input;

said client application performs said step of constructing said recurrence rule to represent said schedule;

said client application transmits said recurrence rule to said server application; and

said server application performs said step of storing data representing said recurrence rule on said storage device.

5. The method of claim 1 wherein a given cycle of said one or more cycles includes a plurality of occurrences of said recurring event, wherein said plurality of occurrences do not occur according to a uniform interval, the method further comprising the step of:

receiving a third input indicating when said plurality of occurrences occur during said given cycle; and

wherein said step of generating said recurrence command to represent said given cycle includes generating an occurrence list representing when said plurality of occurrences occur.

6. The method of claim 5 wherein said occurrence list represents when at least one of said plurality of occurrences occurs with an absolute occurrence specifier.

7. The method of claim 6 wherein said occurrence list includes data representing a weekday and data representing a relative occurrence of said weekday within a month.

8. The method of claim 5 wherein said occurrence list represents when at least one of said plurality of occurrences occurs with a relative occurrence specifier.

9. The method of claim 1 wherein said step of constructing said recurrence rule includes placing said recurrence command in an order based on the length of the cycle represented by said recurrence command for each cycle of said one or more cycles.

10. The method of claim 1 wherein the cycle is repeated N times during said schedule, wherein N represents a non-negative integer, wherein said recurring event takes place on a relative occurrence of a certain weekday in a month, the method further comprising the steps of:

generating a repeat-quantity indicator representing the value of N; and

generating a relative occurrence specifier that indicates said relative occurrence of said certain weekday in said month.

11. A method for representing in an electronic device a schedule of a recurring event, wherein the schedule includes a cycle of a certain duration, wherein the cycle is repeated N times during the schedule, wherein N is at least two, wherein during the first N-1 iterations of the cycle said recurring event occurs at a first set of times and a second set of times, wherein during the Nth iteration of said cycle said recurring event occurs at said first set of times but not at said second set of times, the method comprising the steps of:

generating a time-interval indicator representing said certain duration;

generating a repeat-quantity indicator representing the value of N;

generating an occurrence list including data representing said first set of times and said second set of times;

inserting at least one symbol into said occurrence list to distinguish between said first set of times and said second set of times.

12. The method of claim 11 wherein said step of generating said occurrence list includes generating an occurrence list in which data indicating said first set of times precedes data indicating said second set of times, wherein said step of inserting one or more symbols includes inserting one or more symbols between the data indicating said first set of times and the data representing said second set of times.

13. An apparatus for storing a representation of a schedule of a recurring event, the apparatus comprising:

an input device for receiving input representing said schedule;

a processor coupled to said input device, said processor receiving said input from said input device and generating a recurrence rule based on a grammar, wherein said recurrence rule represents said schedule of said recurring event; and

a storage device coupled to said processor, said processor storing data representing said recurrence rule on said storage device;

wherein said recurrence rule includes one or more recurrence commands, wherein each recurrence command of said recurrence rule represents a repeating cycle in said schedule;

wherein said grammar includes rules for constructing time-interval indicators for representing cycles that repeat every N₁ minutes, every N₂ days, every N₃ weeks, every N₄ months on a relative day and week, every N₅ months on an absolute day, every N₆ years on one or more specific months, and every N₇ years on one or more specific days of the year, where N₁ -N₇ are each any natural number.

14. The apparatus of claim 13 wherein said grammar includes rules for constructing repeat-quantity indicators for representing how many times a cycle repeats in said schedule.

15. The apparatus of claim 14 wherein said repeat-quantity indicators comprise a repeat-quantity symbol and a number.

16. The apparatus of claim 13 wherein said grammar includes rules for constructing occurrence lists, wherein said occurrence lists indicate times that said recurring event occurs during said repeating cycle.

17. The apparatus of claim 16 wherein said grammar includes rules for constructing occurrence lists that represent specific hours in a day, specific weekdays in a week, specific days in a month, specific months in a year and specific days in a year.

18. The apparatus of claim 16 wherein said grammar includes rules for constructing occurrence lists that represent relative occurrences of weekdays in a month.

19. The apparatus of claim 13 wherein said grammar includes rules for specifying any number of occurrences of said recurring event within a repeating cycle in said schedule.

20. The apparatus of claim 13 wherein said grammar includes a first rule for specifying an absolute end time and a second rule for determining an end time by specifying a number of repetitions of each repeating cycle in said schedule.

21. A method for representing a schedule of a recurring event in an electronic device, wherein the schedule includes a plurality of cycles, wherein each of said plurality of cycles has a length, the method comprising causing the electronic device to perform the steps of:

a) for each cycle in said schedule, performing the steps of

a1) generating a time-interval indicator representing the length of said cycle;

a2) generating a recurrence command to represent said cycle, said recurrence command including said time-interval indicator, and

b) constructing a recurrence rule to represent said schedule, wherein said recurrence rule includes the recurrence command generated for each cycle of said plurality of cycles;

wherein;

said schedule includes a first cycle and a second cycle;

said schedule includes repeating one of said first cycle and said second cycle within the other of said first cycle and said second cycle;

said first cycle has a duration that does not vary;

said second cycle has a duration that varies based on a selective relative occurrence;

said step of a1) generating a time-interval indicator includes the steps of

generating a first time-interval indicator representing the length of said first cycle; and

generating a second time-interval indicator representing the length of said second cycle;

wherein said step of a2) generating a recurrence command includes

generating a first recurrence command to represent said first cycle; and

generating a second recurrence command to represent said second cycle;

wherein said step of b) constructing a recurrence rule includes constructing a recurrence rule that includes said first recurrence command and said second recurrence command.

22. The method of claim 21 wherein said selected relative occurrence is a relative occurrence of a weekday in a month.