recurrence

what client(s) should be targeted in implementing an ICalendar export for events?

http://en.wikipedia.org/wiki/ICalendar I'm working to implement an export feature for events. The link above lists tons of clients that support the ICalendar standard, but the "three big ones" I can see are Apple's iCal, Microsoft's Outlook, and Google's Gmail. I'm starting to get the feeling that each of these client implement differe...

What's the best way to model recurring events in a calendar application?

I'm building a group calendar application that needs to support recurring events, but all the solutions I've come up with to handle these events seem like a hack. I can limit how far ahead one can look, and then generate all the events at once. Or I can store the events as repeating and dynamically display them when one looks ahead on th...

How do I use Master theorem to describe recursion?

Recently I have been studying recursion; how to write it, analyze it, etc. I have thought for a while that recurrence and recursion were the same thing, but some problems on recent homework assignments and quizzes have me thinking there are slight differences, that 'recurrence' is the way to describe a recursive program or function. Thi...

Relational Schema for Fowler's Temporal Expressions

Martin Fowler defines an elegant object model for the scheduling of recurring tasks here, which maps to OO code very nicely. Mapping this to a relational database schema for persistence, however, is tricky. Can anyone suggest a schema + SQL combination that encapsulates all the functionality he describes, particularly in the image on p...

What is the best way to specify execution time of recurring jobs or tasks?

I am looking for a way of efficiently specifying a recurring job execution time without having to write an explicit execution time to a datastore. In other words, rather than saying 'job x next runs at 13.00pm on 11.12.08' and then having to update the execution time for the following week once the job has run, I want to be able to say '...

How would you store possibly recurring times?

I need to store whether something happens once, daily, weekdays, weekly, some days of the week, some days of the month, which may be numerical or symbolic, like first Monday of each month, and so on. Any recommendations? Any code, data structure or schema to look at? ...

Whats the best java date recurrence pattern calculator

Anyone know of a (reliable) date recurrence calculator, we're trying to implement something in our app which would allow a schedule to be created, similar to those for recurring meetings in Outlook. We have tried chronos but discovered some cases where it breaks down, I'd really appreciate knowing if anyone has successfully used any of t...

Recurrence rule definition (RFC2445) question

Hi, I'm using Google's RFC2445 implementation (http://code.google.com/p/google-rfc-2445/) for recurrence rules. If I define a MONTHLY recurrence starting on the 30th of January, months with less than 30 days (i.e., February) will be totally skipped. So the Google API would return 30th Jan, 30th March, 30th April, etc. Not good. I would ...

PHP Calendar Recurrence Logic

Before the answers start coming (which I know they will) I know that there are a million projects out there that have done this already. Having said that what I am trying to do is create an online calendar - using PHP & MySQL here is what I am planning ... tables in database ((calendar_item) id, title, start_date, start time, end time...

detecting conflicts in recurring events

Hello all I'm writing a calendar application that needs to check for conflicts between recurring entries. Each Entry object has a recurrences() method which returns an array of ranges - each range contains the start and end times of each future occurrence. I need to check for conflicts between new and existing entries. I'm doing this b...

How to know when Big O is Logarithmic?

My question arises from the post "Plain English Explanation of Big O". I don't know the exact meaning for logarithmic complexity. I know that I can make a regression between the time and the number of operations and calculate the X-squared value, and determine so the complexity. However, I want to know a method to determine it quickly on...

Recurring dates on dates that do not exist

When giving the option for something to reoccur every certain amount of time how should I treat times that don't reoccur on every interval? For example what should happen to birthday reminders for February 29th? Or if I have a monthly appointment on the 31st what should happen on months that do not have a 31st day? What do you believe ...

Recurrence Rule +vCalendar

Recurrence Rule: This property is identified by the property name RRULE. This property defines a rule or repeating pattern for a recurring vCalendar entity, based on the Basic Recurrence Rule Grammar of XAPIA's CSA. The value for the property is a pattern specification for the recurrence. The following is an example of this property: RR...

How to determine the height of a recursion tree from a recurrence relation?

How does one go about determining the height of a recursion tree, built when dealing with recurrence run-times? How does it differ from determining the height of a regular tree? edit: sorry, i meant to add how to get the height of the recursion tree from the recurrence relation. ...

Recurrence Relation

Why is the recurrence relation of recursive factorial algorithm this? T(n)=1 for n=0 T(n)=1+T(n-1) for n>0 Why is it not this? T(n)=1 for n=0 T(n)=n*T(n-1) for n>0 Putting values of n i.e 1,2,3,4...... the second recurrence relation holds(The factorials are correctly calculated) not the first one. Please clear my doubt. ...

Recursion Tree, Solving Recurrence Equations

As far as I know There are 4 ways to solve recurrence equations : 1- Recursion trees 2- Substitution 3 - Iteration 4 - Derivative We are asked to use Substitution, which we will need to guess a formula for output. I read from CLRS book that there is no magic to do this, i was curious if there are any heuristics to do this? I can certa...

Figuring out the next scheduled date for a recurrence rule using Ical4J?

I have a project in which i am allowing users to enter an event of recurrent type and get the details of the recurrence from him. So far in the research I am thinking of using ICal4J for reading and writing the recurrence details in the format of .ics files. I am yet to figure out a way to get the next possible date of scheduling, given...

Is log(n!) = Θ(n·log(n))?

This is a homework question. I'm not expecting an answer, just some guidance, possibly :) I am to show that log(n!) = Θ(n·log(n)). A hint was given that I should show the upper bound with nn and show the lower bound with (n/2)(n/2). This does not seem all that intuitive to me. Why would that be the case? I can definitely see how to...

How should I update an iCal RRULE when moving an appointment?

I'm switching my app's calendar from Telerik Scheduler to jQuery fullcalendar. I'm storing recurring events in the db using iCal RRULEs. The question is, when someone drags an event to a new date, how can I update the RRULE so each subsequent occurrence is bumped by the same time delta? I've looked at DDay.iCal and I see the method Re...

Find recurrence relation of this algorithm?

Assuming n=B-A+1, I need to derive the recurrence relation of this algorithm: void recurringalgorithm(int *a, int A, int B){ if (A == B){ for (int j=0;j<B;j++){ cout<<a[j]; } cout<<endl; return; } for (int i=A;i<B;i++){ dosomething(a[A],a[i]); recurringalgorithm(a,A+1,B); dosomething(a[A],a[i]);...