Baselines and variance

A baseline is a snapshot of the schedule: the start and end dates of every task and sub-task, plus the project’s overall start and end, saved together with the date and time of capture. The live plan keeps changing as work happens; the baseline does not. That contrast is what makes honest tracking possible, because you compare what is happening against what was committed.

A project holds one baseline at a time. Capturing a new one overwrites the old one, and there is no baseline version history inside the project.

There is no control that clears a baseline. Once a project has one, the only way to change it is Re-baseline, which replaces it, and only deleting the project removes it. A copy made with Duplicate starts without a visible baseline, as the next section explains.

Only the project owner can capture a baseline. For editors the button is disabled, with a tooltip that reads "Only the project owner can set a baseline". The button is also disabled while the project has no tasks, because there is nothing to capture yet.

1. Finish any date changes you want the baseline to reflect. The usual moment is right after the plan is approved.
2. Click Set Baseline in the toolbar.

The capture happens immediately; there is no confirmation step the first time. A Baseline Set toast confirms that the current schedule was captured, and the capture date and time are stored with the project.

Right after a capture, each baseline bar has the same dates as its live bar and sits exactly behind it, so the chart looks unchanged. A note in the corner of the chart says "Baseline saved. Its gray bars sit behind the live bars and show once a date moves." It goes away once a date moves. Close it with its X and it stays closed in this browser until you capture a new baseline. Only people who can edit the project see the note.

Duplicating a project does not carry a working baseline over to the copy. The copy keeps each task’s baseline dates but not the capture time, so it shows no gray baseline bars and no variance in tooltips, and its toolbar reads Set Baseline. Click it on the copy to capture the copy’s own baseline. Until you do, a portfolio’s List view still reports the copy’s Baseline Status against the dates it inherited from the original.

Once a baseline exists, the toolbar button label changes from Set Baseline to Re-baseline. Clicking it opens a confirmation dialog titled Re-baseline Schedule, which shows the exact date and time the previous baseline was captured and warns that overwriting it cannot be undone. Click Re-baseline to confirm, or Cancel to keep the current baseline. A Baseline Updated toast confirms the new capture.

Once a baseline exists, gray baseline bars draw behind each task’s live bar, and a Baseline switch with a signpost icon appears in the Gantt header. Its tooltip reads Show Baseline or Hide Baseline, and the button is filled while the baseline is shown. On a computer the button shows the word Baseline only once you drag the task list well past its starting width, about a seventh wider; at the starting width, and on a phone, it shows the icon alone. The switch only appears once a baseline has been set.

The baseline is shown by default. Ganttastic remembers your choice for each project in this browser, so a baseline you hid stays hidden after a reload. The choice is not saved to the project, so each collaborator keeps their own.

Baseline milestones render as smaller gray diamonds behind the live diamond.

With the baseline visible, each task shows two bars: the gray baseline bar behind and the live bar in front. Read them together.

• Live bar sits to the right of the baseline bar: the task is running later than planned.
• Live bar sits to the left: the task is running earlier than planned.
• Live bar is longer: the work has stretched.
• Live bar is shorter: the work has been compressed.

For exact numbers, hover over any task. When a baseline is visible, the tooltip reports start and end variance in working days, for example "Start: 3 working days late" or "End: 2 working days early". Late variance shows in red and early variance in green. The day counts respect your project’s Work Calendar, so weekends and custom holidays are not counted.

• Capture the baseline the moment the plan is approved, before work starts. A baseline set halfway through the project has already absorbed the early slip.
• Keep the baseline visible in status meetings, so the discussion compares reality against the commitment rather than against last week’s revision.
• Re-baseline rarely, and only for genuine plan changes such as an approved scope change or a formally agreed new end date. If you re-baseline every week, variance always looks clean and the baseline stops telling you anything.