OK, let's say I am writing a calendar application in which a user can create an event. An event can occur in the following situations:
1 time only.
Every Period of time keep reply, until a day.
Every Period of time keep reply, until a day, except some days.
Every some kind of week day.
Let me explain in a detailed example:
1 time only: 24/8/2011 ONLY.
Every Period of time keep reply, until a day: 25/8/2011 Start, and every week end will have this event, until 30/10/2011.
Every Period of time keep reply, until a day, except some days: 25/8/2011 Start, and every week end will have this event, until 30/10/2011, except the 10/09/2011 and 17/09/2011.
Every some kind of week day, .
Every some kind of week day, except some days.
Martin Fowler wrote a nice big article about just this topic a few years ago. Rather than repeat his analysis, I'll just point you at the pdf. It's called Recurring Events For Calendars.
Related
I’m a data analyst in the insurance industry and we currently have a program in SAS EG that tracks catastrophe development week by week since the start of the event for all of the catastrophic events that are reported.
(I.E week 1 is catastrophe start date + 7 days, week 2 would be end of week 1 + 7 days and so on) then all transaction amounts (dollars) for the specific catastrophes would be grouped into the respective weeks based on the date each transaction was made.
Problem that we’re faced with is we are moving away from SAS EG to GCP big query and the current process of calculating those weeks is a manually read in list which isn’t very efficient and not easily translated to BigQuery.
Curious if anybody has an idea that would allow me to calculate each week number in periods of 7 days since the start of an event in SQL or has an idea specific for BigQuery? There would be different start dates for each event.
It is complex, I know and I’m willing to give more explanation as needed. Open to any ideas for this as I haven’t been able to find anything.
I had a question regarding SQL and if you could code it properly to do auto scheduling.
Example
A shipment could come to a store Monday-Friday, but there could only be a certain amount of shipments during this week and it depends which worker was available. I'll run down things in order that way it's not too confusing.
A) A shipment can only stop twice a day, but it cannot stop on a day that has any shipments the day before or the day after. So if Monday had 2 shipments, there would be no stops on Tuesday. If Wednesday has 2 shipments, you could not have any stops Tuesday/Thursday.
B) A shipment can only be so big on these days. If two shipments are both UNDER 1000 pounds, then we can schedule both, but if a shipment is OVER 1000 pounds, then we can only schedule one for that day.
C) One of the two workers must unload each shipment. So lets say that A already has 1 shipment on Monday, I need it to go to B for the 2nd shipment on that Monday.
I understand that SQL cannot accept user input directly, so don't worry about this. Using getdate() would be sufficient enough.
I started on this code and got a little bit in, but the while loop was running for forever (>30 seconds) and I thought it was almost impractical at that point.
Curious if this is doable and the best approach to do this. I'm assuming that C# or something would be loads easier to do with, but wondering about SQL.
Thanks in advance.
I have an APScheduler job that creates a report our client has requested for the first and third Mondays of the month.
To deliver that in time, I want to run the job the day before the first and third Monday, which can't be specified directly in APScheduler.
I noticed another user had this question as well, describing the request as impossible, in the comments of Running APScheduler Job Every nth Day of Month
Here's how I solved it:
scheduler.add_job(func, 'cron', 'day_of_week'='sun', 'day'='last,1-6,14-20')
By specifying the day of the week, and then specifying the days in the month that could apply, it will fire the day before the first and third Mondays. It only fires when all the conditions are met, so the other dates (which won't be Sunday) don't fire.
I need to create a T-SQL (I`m using SQL Server 2008 Express) script (procedure/function) that takes entries from a "Tasks" table and generates only the tasks planned to occur in the next 5 hours.
In the "Tasks" table I should have tasks with job like properties :
Occurrence : One time or Recursive
Frequency : every x Days, Weeks, Months
Depending on the Frequency :
For Daily : every x hours,minutes
For Weekly -Days of the week when the task should occur
For Monthly - The first,second,last -day,week day,weekend -
day of week OR The 1st, 2nd, 3rd..31st of the month.
When I run the script I should get only the tasks that will occur in the next 5 hours or less in the case if task occurs every x minutes.
So what this script should actually do is use all the options from a SQL Server Job for a task.
Example1: I create a task "Check email" that occurs every day, between 14:00 and 15:00 . When i run the script at 09:00 I would get Task:"Check email" Time:5 hours left until task, because it occurs every day, i should be able to get this result every day when I roll the script ,only if that 5 hours or less range .
Example2: A task "Send hours report" that occurs Monthly, on the 1st week day (not weekend), at 01:00 PM . Running the script on the first week day of the month at 08:00 AM I should get Task:"Send hours report" Time:5 hours until task
I know it's a quite big request but hopefully someone will find it easy what for me seems pretty hard.
You should also store somewhere the date/time of the last execution of each job (at least for jobs that are configured for every x hours/minutes). The idea is to calculate the next execution date/time for each job, and return it if it's less than 5 hours away. If the job is configured for every x hours/minutes, use DATEADD and check if the result is within the configured timeframe. If the job is configured for daily (at a specified time), just check if the specified time is less than 5 hours away (but still in the future). I have done a similar feature and it's not an easy thing to check for all cases (it took me a few days of coding).
I've started thinking about an employee shift management application to handle the shifts (who works when, trading, etc) at my current workplace (that uses pen and paper and hasn't got anyway for us employees to communicate about changes without going through the boss and be on site).
Currently the shifts are modeled loosely as:
There is a recurring 4 week period (from Monday week 1 to Sunday week 4)
There is a template for placing employees in this 4 week period
Every 4 months (ie 3 times a year) the 4 week template is projected over the next 4 month period
The shifts have been the same for a long time and it seems many employees would prefer to have them changed (I can say this by the requests for change that come in every time a new 4 month is set).
What I'm aiming at are the models:
Shift_group_tpl (the 4 week period above)
Shift_tpl (a single shift in the 4 week period, including info on who defaults to work this shift)
Shift_group (a set period of time whit actual shifts)
Shift (a set shift whit a real time period and an employee - and the possibility to be changed both in start_time, end_time and employee)
I've thought of a way to do this with recurring iCalendar events: Creating RRULE's (without an endtime) and then calculate (using temporary start and end times) if that specific Shift_group_tpl could be used within a real Shift_group. (The problem with this approach is that I can't figure out how to trim the Shift_group_tpl's to fit into the start or end of a Shift_group.)
What I'm looking for are some other perspectives or ways of doing it or even just a pat on the shoulder letting me know that I'm on the right track (and then giving advice on the trimming problem).
/iole1
What I'm aiming at are the models:
Shift_group_tpl (the 4 week period above)
Shift_tpl (a single shift in the 4 week period, including info on who defaults to work this shift)
Shift_group (a set period of time whit actual shifts)
Shift (a set shift whit a real time period and an employee - and the possibility to be changed both in start_time, end_time and employee)
You have "sql" as a tag for this post? So im guessing you want these as SQL tables?
By the sounds, the problem is that your considering the data you have, rather than the abstract concepts you need to store that data. Which is what you'd need to do to create an application. (Most likely a "Shifts" table, rather than the four tables above).
There is little information here to help, Consider refining your thoughts and ask another question.