Just a question for the experienced programmers.
I'm creating a scheduling software.
I have a start date and a number of days it takes to complete the task and I want to calculate the end date.
Easy enough.
However, I want to subtract weekends and holidays.
My instinct is to have two lists, one of days that have passed and one for the weekends/holidays to skip, and for each day that passes check to see if it's a holiday or a weekend and skip it.
But that seems like it would scale exponentially.
Wondering how an experienced programmer would implement this.
Okay,
We have list of Holiday in a table.
We have start date.
we have number of days to complete task.
Initialize counter to 0
Loop counter till no of days to complete is reached
1. Increment start date with one.
2. Skip 4 if it belongs to Holiday.
3. Skip 4 if it is weekend.
4. increment the counter
Print start date as End date
Related
I need to alternate between 2 tasks every day, and I need a simple algorithm to know which task I need to do.
I need to be able to run this algorithm by head, using simple general knowledge (like day of week, day of month, etc), and it must not rely of which task has been done the previous day (because I have a crappy memory).
I have tried checking for parity in a combination of day of week / day of month / # of month, etc, but couldn't find a suitable system: day of week have 2 consecutive odd numbers, same goes for day of month every so often.
I am afraid that this is impossible: if you can't remember what you did the day before, any other procedure will require more mnemonic effort.
remember what you did on January first (or another date),
remember the parities of the cumulated months: oeoeoeooeoe or ooeoeoeeoeo for a leap year,
add the cumulated parity of the month before* to the parity of the day,
add that to the parity of the first task.
E.g. if A on January 1st 2022, then on March 17, 2022: e + o = o gives B.
*In January, use even.
You can also state the month parity rule as: until August inclusive, use the co-parity of the month number; then use the parity. But for a leap year, change that parity after February (excluded).
I need to be able to run this algorithm by head
So, you don't need to take help of Computer science. You can use cognitive human ability to map a thing to another thing.
Note: This need not make sense to everybody though, if you are thinking out of the box.
Map task 1 as God's day.
Map task 2 as Devil's day in your brain.
This should be simple just like day and night.
Now, remember that devil's evil karma is always burnt by God the next day and that devil never learns his lesson. So this way, alternating would be easy.
Friends Episode snippet on Youtube
Just count the number of days in between your date and a given "zero" one...then use parity.
Take number of seconds (or milli, or whatever) since EPOCH (common zero for date and time), divide (integer division) by 60x60x24 (or 1000x60x60x24, or what is appropriate), you then get the number of days since EPOCH.
----EDIT----
Example: Got 1653910695 seconds since EPOCH (at the time of my experience). Dividing it by 60x60x24 give 19142 days. To morrow it will give 19143, etc.
<?php
$day = Date('j');
$previous_day = date('j', strtotime("-1 days"));
if($day%2==0 OR $previous_day%2!=0)
echo "Task 1";
}else{
echo "Task 2";
}
?>
How to write an interval that groups by every half a month? Rather than 1M I want something like 1/2M to group by from the first to the 16th and from the 16th to the end of the month, every month. Is there a way to do so?
I don't want to end up doing an interval on each day and then calculate manually my results as it's not clean and it would be resource hungry, is there a simple way to do so using setInterval? (in Elasticsearch or Elastica I don't care, I just want the algorithm behind it, thanks!)
$date_grp_agg = new \Elastica\Aggregation\DateHistogram('date');
$date_grp_agg->setField('date')->setFormat("MM-yy")->setInterval('1M'); // This one
Unfortunately, neither 0.5M (half month) nor 2w (2 weeks) are supported, but you could try to use a number of days, i.e. 15d.
$date_grp_agg->setField('date')->setFormat("MM-yy")->setInterval('15d');
Granted, it will not fit months perfectly, i.e. it won't start on the 1st and end on the last day of the month, but it can get you close to the kind of interval you're looking for.
I have a sheet where I record my working hours (this is more for me to remind me to stop working than anything else). For every day, I have three possible shifts - early, normal & late, and I have a formula which will sum up any times put into these columns and give me the daily total hours.
To summarise the duration of time spent working in a day, I use the following formula: =(C41-B41)+(E41-D41)+12+(G41-F41) which is:
early end time minus early start time
normal end time minus normal start time PLUS 12 hours
late end time minus late start time
Which gives me output like this:
What I cannot seem to achieve is, the ability to sum the daily totals into something which shows me the total hours worked over 1-week. If I attempt to sum the daily totals together for the example image shown, I get some wild figure such as 1487:25:00 when formatting as 'Duration' or 23:25:00 when formatted as 'Time'!
All my cells where I record the hours worked are formatted as 'Time'
When using arithmetic operations on date values in Google Sheets, it's important to remember that the internal representation of a date is numeric, and understood as the number of days since January 1, 1970.
What follows from that, is that if you want to add 12 hours to a time duration, you should not write "+12" because that will in fact add 12 days. Instead add "+12/24". In other words, try the following formula instead of the one you are using now:
=(C41-B41)+(E41-D41)+(12/24+G41-F41)
I will try to explain what I want to accomplish. I am looking for an algorithm or approach, not the actual implementation in my specific system.
I have a table with actuals (incoming customer requests) on a daily basis. These actuals need to be "copied" into the next year, where they will be used as a basis for planning the amount of requests in the future.
The smallest timespan for planning, on a technical basis, is a "period", which consists of at least one day. A period always changes after a week or after a month. This means, that if a week is both in May and June, it will be split in two periods.
Here's an example:
2010-05-24 - 2010-05-30 Week 21 | Period_Id 123
2010-05-31 - 2010-05-31 Week 22 | Period_Id 124
2010-06-01 - 2010-06-06 Week 22 | Period_Id 125
We did this to reduce the amount of data, because we have a few thousand items that have 356 daily values. For planning, this is reduced to "a few thousand x 65" (or whatever the period count is per year). I can aggregate a month, or a week, by combining all periods that belong to one month. The important thing about this is, I could still use daily values, then find the corresponding period and add it there if necessary.
What I need, is an approach on aggregating the actuals for every (working)day, week or month in next years equivalent period. My requirements are not fixed here. The actuals have a certain distribution, because there are certain deadlines and habits that are reflected in the data. I would like to be able to preserve this as far as possible, but planning is never completely accurate, so I can make a compromise here.
Don't know if this is what you're looking for, but this is a strategy for calculating the forecasts using flexible periods:
First define a mapping for each day in next year to the corresponding day in this year. Then when you need a forecast for period x you take all days in that period and sum the actuals for the matching days.
With this you can precalculate every week/month but create new forecasts if the contents of periods change.
Map weeks to weeks. The first full week of this year to the first full week of the next. Don't worry about "periods" and aggregation; they are irrelevant.
Where a missing holiday leaves a hole in the data, just take the values for the same day of the previous week or the next week, and do the same at the beginning/end of the year.
Now for each day of the week, combine the results for the year and look for events more than, say, two standard deviations from the mean (if you don't know what that means then skip this step), and look for correlations with known events like holidays. If a holiday doesn't show an effect in this test then ignore it. If you find an effect, shift it to compensate for the different date next year. Don't worry about higher-order effects, you don't have enough data to pin them down.
Now draw in periods wherever you like and aggregate all you want.
Don't make any promises about the accuracy of these predictions, there's no way to know it. Don't worry about whether this is the best possible way; it isn't, but it's as good as any you're likely to find. You can spend as much more time and effort fine-tuning this as you wish; it might raise expectations but it's not likely to make the results much more accurate-- it's about as likely to make them worse.
There is no A-priori way to answer that question. You have to look at your data, and decide what the important parameters (day of week, week number, month, season, temperature outside?) using the results.
For example, if many of your customers are jewish/muslim, then the gregorian calendar, and ISO-week numbers and all that won't help you much, because jewish/muslim holidays (and so users behaviour) are determined using other calendars.
Another example - Trying to predict iPhone search volume according to last year's search doesn't sound like a good idea. It seems that the important timescales are much longer than a year (the technology becoming mainstream over the years) and much shorter than a year (Specific events that affect us for days-weeks).
I have the following question, and what I'm most confused on, is how to do the logic for determining if a check is one month late or not.
Question is:
"Write pseudocode for a program that calculates the service charge of a customer owes for writing a bad check. The program accepts a customer's name, the date the check was written (year, month and day), the current date (year, month and day), and the amount of the check in dollars and cents. The program continues until an eof value is encountered. The service charge is $20 plus 2 percent of the amount of the check, plus $5 for every month that has passed since the check was written. A check is one month late as soon as a new month starts-so a bad check written on September 30 is one month overdue on October 1."
So far what I have write now is:
Start
string Name
num AmountOwed
num DateCheckWritten
num CurrentDate
num CheckAmount
get Name, DateCheckWritten, CurrentDate, CheckAmount
while eof
Since you don't have to deal with days, the algorithm is very straightforward:
MonthsLate = (CurrentDate.Year - DateCheckWritten.Year) * 12
+ (CurrentDate.Month - DateCheckWritten.Month)
Good luck with the rest of the problem!
I'm not sure where your problem lies, but I think you have two issues to deal with:
What is the definition of late?
How many months late is this check?
So in my pseudocode, I would have a step that determines how late a check is, and then another step to calculate the fee. Inside the first step, you could just subtract the days and divide. But the directions say as soon as a new month comes along, it is one month late. So all you really have to do is subtract months.
Not sure what else you are asking, but it appears you are asking for guidance, not code. Hope this helps.
I'm going to assume this is homework, and as such I'll try to just point you in the right direction.
If you assign numbers to each month (Jan = 1, Feb = 2, etc) then the number of months between two dates is easy to determine - how many months are there between September (= 9) and May (= 5)?
The other thing to take into account is the year - for each year the check is late, you'll also have to add another twelve months. This works the same as for months.
Need any extra detail, feel free to let me know.
Simplify, hit the main points and then break it down more and more, write it how you would tell your grandma it worked.
you might start out with something like
Start
While there are more bad checks
get the service charge
add the service charge to the account
record the updates
get the service charge
charge starts at $20
add to the charge $5 multiplied by number of months