Calendar Setup

Configure working days / non-working days that affect how Auto Calc computes a task's Finish date. Built-in presets for Vietnamese public holidays (Lunar New Year, Apr 30 - May 1, Sep 2, ...).

Available in Standard

Calendar Setup is a basic feature shared with Gantt Chart — does NOT require Pro tier.

Open the dialog

DVD Cons → group Schedule → click Schedule Settings.

4 configuration sections

1. Workweek

Check/uncheck days of the week as WORKING days. Defaults follow VN construction industry norm:

Day	Default	Notes
Monday	✓	Full working day
Tuesday	✓
Wednesday	✓
Thursday	✓
Friday	✓
Saturday	✓	Working on VN sites (differs from Western norm)
Sunday	☐	Not working

Switch to 5-day-week when project is office-style or international.

2. Holidays

List of specific calendar days as NON-WORKING. Two ways to add:

Method A — VN preset: click "Add VN 2026 holidays" → dialog adds 11 days:

Holiday	Date	Days
New Year's Day	Jan 1	1
Lunar New Year	6 days around Lunar Jan 1	6
Hung Kings' Festival	Lunar Mar 10	1
Reunification + Labor Day	Apr 30, May 1	2
National Day	Sep 2, Sep 3	2

Preset also includes compensation days (when holiday falls on weekend).

Method B — Manual: click "➕ Add" → pick a date + name.

3. Default calendar per project

Each project can use its own calendar. Config is saved in the workbook (sheet Mucluc cells B33-B35 or CustomXMLPart):

DefaultCalendar = "VN_2026"
Workweek = "Mon,Tue,Wed,Thu,Fri,Sat"
Holidays = "2026-01-01,2026-02-15..2026-02-20,..."

When opening another project file → addin reads its config → applies the right calendar.

4. Auto Calc respects calendar

When Auto Calc = ON and user enters:

• Start = 2026-04-29 + Duration = 5
• → Finish is NOT 2026-05-04 (5 calendar days)
• → Finish = 2026-05-06 because Apr 30 and May 1 are holidays (Auto Calc skips them)

Effect on Pro modules

After upgrading to Pro:

• EVM Report: PV/EV computed by working day → not inflated when many holidays in period
• 3-Week Lookahead: includes 15-21 working days (not 21 calendar days)
• Schedule Recovery: crash duration computed on working days
• Shared calendar config: configure once → both Std (Gantt) and Pro (EVM, Recovery) use it

Tips

• Company-specific holidays (e.g. founding anniversary): add manually with custom name
• Shift work: if site runs 2 shifts/day → don't change calendar, instead set resource × 2 in column I of the Input table
• Export to MS Project: exported .mpp preserves calendar config
• Reset to defaults: delete the Mucluc config sheet → reopen workbook → addin re-applies VN defaults

Related

• Gantt Chart — draw Gantt with this calendar config
• Schedule Pro — EVM / Lookahead / Recovery also use the calendar