Ganttly Project Timeline

Use this when the user wants a Gantt chart, project timeline, project schedule or project plan with milestones from a task list, wants to find the critical path and project duration, or asks for early start, early finish, late start, late finish, total float or free float (critical path method). Takes tasks with durations (days or weeks), finish-to-start dependencies with optional lags, optional start-no-earlier-than dates, owners and milestones, plus a start date and a business-day calendar with country public holidays or calendar days. Returns every task's dates and float, the critical path, milestones and the end date, an interactive Gantt chart, and CSV, .ics and SVG downloads. Detects dependency loops and unknown task names. Does not save projects, sync with project tools, track progress, or level resources. Do not use for a single date difference or for daily to-do planning.

Use this when the user asks what happens to a project schedule if a task slips, takes longer or shorter, or starts later: for example "if Design slips 5 days, when do we finish?" or "does the critical path change?". Takes the same task list and calendar as plan_project_timeline plus 1 to 4 scenarios, each with changes (extra_days, a new duration, or a new start-no-earlier-than date). Returns the baseline and each scenario's end date, the delay in working and calendar days, the new critical path, tasks that became or stopped being critical, and how much of each slip was absorbed by float. Does not change or save the plan. Do not use for the first schedule of a project (use plan_project_timeline).