Open Planner Studio v2026.7.6

What's New in v2026.7.6

This release delivers phase 2.8a: calendars — year-independent holidays for seven countries, a real calendar library, and task-specific calendars in the scheduling engine.

Calendars

• Year-independent holiday generation: holidays are generated from rules (fixed dates, Easter-based, nth-weekday, substitution rules) for the whole project period — no more silently holiday-free years. The default calendar finally includes Christmas.
• Seven country sets: Netherlands, Germany (per Bundesland — Fronleichnam in Bavaria, Reformationstag in the north, and so on), Belgium, France, United Kingdom (per nation, with bank-holiday Monday substitutions), Austria and Switzerland (per canton, common set).
• Dutch construction holiday (bouwvak) is now opt-in: new projects contain no bouwvak unless you pick a region (North/Central/South) in the wizard — previously three weeks of regio-Noord holiday were silently baked into every new project. The dates come from a verified table of published advisory dates (2025–2028), correctly following the yearly region rotation, with a clear "advisory dates" hint.
• Calendar library: one set of named calendars per project, shared by the project default, tasks and resources. Manage them in the calendar dialog: create, duplicate, rename, delete, set as project default, and generate holidays for any calendar. One-click Continuous (24/7) and Mon–Fri presets.
• Task-specific calendars: give any task its own calendar (e.g. indoor work continuing through a winter shutdown). The scheduler computes each task's duration in its own calendar; relation lag counts in the predecessor's calendar (P6 convention), and float is reported in each task's own work days. Levelling previews remain exact.
• Project wizard: country/region choice, bouwvak choice (default none), optional fixed winter shutdown, and a holiday preview before the project is created.
• Holiday names in the Gantt: multi-day holiday blocks now show their name in the shading (e.g. "Bouwvak (Noord)"), so a three-week gap is no longer a mystery.

Interoperability

• IFC reader gap fixed: working days and daily hours now survive the round-trip (a 6- or 7-day calendar previously reset to Mon–Fri on load).
• Multiple named calendars and task→calendar assignments round-trip through IFC 4.3, MS Project (MSPDI) (task CalendarUID) and Primavera P6 XML (per-activity calendar, plus work weeks and holiday exceptions that were previously not exported at all). Files without these features stay byte-identical.

Fixed

• Task bars could vanish from the Gantt after an extreme zoom-out/zoom-in/scroll sequence — scrolling is now clamped to the content bounds.
• Undoing a calendar addition after making it the project default no longer leaves the project pointing at a non-existent calendar.

Quality

• Scheduling regression suite grown from 280 to 290 hand-computed cases (all green), now covering multi-calendar CPM (forward and backward), the predecessor-calendar lag rule, per-calendar float and holiday-rule generation (Easter table, King's Day Sunday rule, UK substitutions, lustrum years).
• All new UI text translated in 14 languages.

Downloads

• Windows: Download the .exe setup file
• macOS: Download the .dmg file (universal - supports Intel and Apple Silicon)
• Linux: Download the .deb package, .AppImage or .snap

Existing installations update automatically via the in-app updater — release notes are now shown right in the update dialog.