Flex: Calculate hours between 2 times?

Question

I am building a scheduling system. The current system is just using excel, and they type in times like 9:3-5 (meaning 9:30am-5pm). I haven't set up the format for how these times are going to be stored yet, I think I may have to use military time in order to be able to calculate the hours, but I would like to avoid that if possible. But basically I need to be able to figure out how to calculate the hours. for example 9:3-5 would be (7.5 hours). I am open to different ways of storing the times as well. I just need to be able to display it in an easy way for the user to understand and be able to calculate how many hours it is.

Any ideas?

Thanks!!

Answer 1

Quick dirty ugly solution

public static const millisecondsPerHour:int = 1000 * 60 * 60;

private function getHoursDifference(minDate:Date, maxDate:Date):uint {
  return Math.ceil(( maxDate.getTime() - minDate.getTime()) / millisecondsPerHour);
}

Answer 2

Ok it sounds like you're talking about changing from a schedule or plan that's currently developed by a person using an excel spreadsheet and want to "computerize" the process. 1st Warning: "Scheduling is not trivial." How you store the time isn't all that important, but it is common to establish some level of granularity and convert the task time to integer multiples of this interval to simplify the scheduling task.

If you want to automate the process or simply error check you'll want to abstract things a bit. A basic weekly calendar with start and stop times, and perhaps shift info will be needed. An exception calendar would be a good idea to plan from the start. The exception calendar allows holidays and other exceptions. A table containing resource and capacity info will be needed. A table containing all the tasks to schedule and any dependencies between tasks will be needed. Do you want to consider concurrent requirements? (I need a truck and a driver...) Do you want to consider intermittent scheduling of resources? Should you support forward or backward scheduling? Do you plan to support what if scenarios? (Then you'll want a master schedule that's independent of the planning schedule(s)) Do you want to prioritize how tasks are placed on the schedule? (A lot of though is needed here depending on the work to be done.) You may very well want to identify a subset of the tasks to actually schedule. Then simply provide a reporting mechanism to show if the remaining work can fit into the white space in the schedule. (If you can't get the most demanding 10% done in the time available who cares about the other 90%)

2nd Warning: "If God wrote the schedule most companies couldn't follow it."