Holiday calendars represent the dates, other than weekends, when your workers are normally off on holiday and not working. For example if Dec 25th is a holiday then the number of "working days" between Monday December 24, 2018 and Friday December 28, 2018 is 4, not 5. Holiday calendars are set up in discussion with your implementation consultant and then assigned to the work-schedules which are in turn assigned to your resources.

It is recommended at a minimum to set up one holiday calendar per country with all resources based in that country adopting that holiday calendar. If some countries have just a handful of resources who are perhaps managed from another country, then it may not be worth the effort of setting up a holiday calendar for so few resources. Just use the closest country holiday calendar instead.

Holidays are defined based on discrete dates on a year by year basis, since they often move around from year to year. Consequently it is  important to set up your holiday calendars at least as far as you may wish to bid for projects on, plus 5-10 years, to be safe. If your HR department has not published company holidays going out that far use this link instead.

Working days or holidays are used to convert dates into a duration and working times or schedules are used to convert duration into effort. For example if a task lasts from December 1 until December 31, 2018 then the duration could be 21 days (no holidays), 20 days (Christmas day only as a holiday) or even 18 days (if Christmas eve, Christmas day and New Year's eve are all holidays). The effort you can get from 1 full-time equivalent or FTE resource is therefore:

• 168 hours in December if they work 8 hrs/day or 40 hrs/week and take no holidays, or
• 150 hours in December if they work 7.5 hrs/day or 37.5 hrs/week and take Christmas day off

These are examples only. The actual effort is calculated as duration in working days times the number of hours per day for that resource if full-time, excluding overtime.  Equally if you maintain the effort then the FTE is calculated as the effort (in hours) divided by the duration (in working days) times the hours per day for that resource.

All efforts and duration are stored internal in hours not days so if you create reports to directly extract the underlying data you will see durations already as number of working hours (days times hours per day for that resource)

You may assign a  mixture of resources from different departments or countries with different working times to the same estimate or BOE-WBS.