To show start and end times as horizontal ranges in Numbers for Mac, build a stacked bar chart from two calculated values: a start offset and a duration. Make the offset blend into the background so the visible bar runs from start to finish.

This tutorial uses a small, illustrative project schedule. The construction combines Apple’s documented stacked charts, formulas, and series formatting; it is a derived technique. Apple’s current online Numbers User Guide for Mac identifies the covered version as Numbers 15.4.

How do offsets and durations create a time range?

A stacked bar places one series after another. For each task, the first segment represents the time between a shared origin and the task’s start. The second represents the task’s duration. Apple documents that stacked bar charts combine two or more series in a stack. Add column, bar, line, area, pie, donut, and radar charts in Numbers on Mac.

The geometry is straightforward:

  • Start offset = start time minus origin.
  • Visible width = end time minus start time.
  • Right endpoint = offset plus width.

For example, take an origin of 08:00. A task running from 09:00 to 10:30 needs an offset of 1 hour and a visible width of 1.5 hours. Its right endpoint is 2.5 hours after the origin. Stacking the start and end values themselves would produce the wrong endpoint because the chart adds the segments.

Use an origin at or before every task’s start. This keeps offsets nonnegative and gives the chart a consistent interpretation. The example uses an elapsed-hours axis: a value of 3 means three hours after the stated origin.

Set up the sample schedule and helper formulas

Create a blank spreadsheet with a table containing at least seven columns and four rows. Use row 1 for headers and column A for task labels. Arrange the columns as follows; leave columns B and C empty until you enter the formulas.

Row A: Task B: Offset hours C: Duration hours D: Start E: End
2 Layout Calculate below Calculate below November 2, 2026 09:00 November 2, 2026 10:30
3 Model assembly Calculate below Calculate below November 2, 2026 09:30 November 2, 2026 12:00
4 Label design Calculate below Calculate below November 2, 2026 11:00 November 2, 2026 13:30

Leave column F empty. In G1, enter Origin; in G2, enter November 2, 2026 08:00. Enter the dates using a format recognized by your Mac’s region settings, and confirm that Numbers recognizes them as dates rather than text.

Select D2:E4 and set Format → Cell → Data Format to Date & Time. Apply the same format to G2. Initially display both the date and time. Apple explains that hiding a date does not remove it from calculations, and entering only a time adds today’s date by default. Explicit dates prevent an unintended day difference. Format dates, currency, and more in Numbers on Mac.

Calculate the start offset and visible width

In B2, enter this formula:

=DUR2HOURS(D2-$G$2)

In C2, enter this formula:

=DUR2HOURS(E2-D2)

The subtraction gives the elapsed duration; DUR2HOURS converts it to a numeric number of hours. This keeps both plotted series in the same unit. Apple defines the conversion in DUR2HOURS.

To enter a formula, select its destination cell, type =, complete the expression, and press Return. The origin reference $G$2 must remain fixed when you fill down. If you build the reference by clicking G2, select its reference token and use Command-K to preserve both its row and column. Calculate values using data in table cells in Numbers on Mac.

Select B2:C2, move the pointer over the selection border until the yellow autofill handle appears, and drag down through row 4. Fill only the intended empty destination cells: Apple notes that autofill overwrites existing content. These are individual cell formulas; the procedure does not depend on array expansion. Autofill cells in Numbers on Mac.

Your calculated values should match this table. The final column is an arithmetic check, not an additional chart series.

Task Offset hours Duration hours Right endpoint: hours after 08:00
Layout 1 1.5 2.5
Model assembly 1.5 2.5 4
Label design 3 2.5 5.5

Set B2:C4 to the Number data format. Keep enough decimal places to inspect partial hours. In this example, 1.5 hours means one hour and thirty minutes; it does not mean 01:50.

Build the horizontal stacked bar chart

Chart only the task labels and calculated numbers in A1:C4. Keep the original dates and origin outside the chart’s data selection.

  1. Click Chart in the toolbar and choose 2D.
  2. Choose a horizontal stacked bar chart. Avoid a percentage-stacked style, which would express proportions instead of elapsed hours.
  3. Click Add Chart Data and select A1:C4.
  4. Choose Plot Columns as Series in the pop-up menu at the bottom of the window.
  5. Click Done.

Apple documents this chart-first workflow, including selecting source cells and choosing the series orientation. Your chart should have three task categories and two numeric series. Add column, bar, line, area, pie, donut, and radar charts in Numbers on Mac.

Check the stack order while both series are still visible. The offset must come first, followed by duration. If needed, use Format → Series → Data → Order to change the series order. Use Edit Data References to correct an accidental selection of the original start or end columns. Modify chart data in Numbers on Mac.

Make the offset blend into the chart background

Use a plain, solid background for this construction. With the chart selected, open Format → Chart and expand Background & Border Style to set its background color. White is a convenient choice. Apple documents background formatting for 2D bar charts in Add a border and background to a chart in Numbers on Mac.

Click an offset segment, then open Format → Style. Give that series a solid fill matching the background, remove its visible outline, and disable any shadow. Select the duration series and give it a distinct solid color. Apple documents series fills, outlines, shadows, and selecting a series through one of its elements. Change the look of bars, wedges, and more in Numbers on Mac.

The offset remains part of the stack. Its matching color creates the floating-range appearance. Because this method uses an opaque matching fill, gridlines behind the offset can appear interrupted; omit them for a cleaner result. Recheck the match whenever you change the chart background.

Keep the offset cells available to the chart. Hiding a source column can change what is plotted: Apple says hidden or filtered data is excluded by default, with a Hidden Data option available under Chart Options. Modify chart data in Numbers on Mac.

Make the time scale and labels understandable

Use a title such as Project schedule — hours after 08:00, November 2, 2026. To display and edit it, select the chart, enable Title in Format → Chart, then double-click the title. This wording makes the numeric horizontal axis unambiguous. Change the look of chart text and labels in Numbers on Mac.

Read the finished chart against these expected positions:

  • Layout starts at 1 and ends at 2.5.
  • Model assembly starts at 1.5 and ends at 4.
  • Label design starts at 3 and ends at 5.5.

Leave value labels off initially. A duration label describes the visible segment’s width, so a value of 2.5 means two and a half hours, not an end time. Apple also supports stack summary labels; here, their sum would represent hours from the origin to the end. Keep the original start and end columns alongside the chart when exact clock times matter. Change the look of chart text and labels in Numbers on Mac.

For axis markings, select Format → Axis, then choose Value or Category. Apple documents gridline and tick-mark controls there. A stacked chart cannot use Apple’s built-in reference lines, so this construction does not support adding a native reference line for a chosen schedule time. Add a legend, gridlines, and other markings in Numbers on Mac.

Diagnose incorrect ranges before adding more tasks

Check the numbers before adjusting the chart’s appearance. The following sequence separates input problems from chart configuration problems.

Symptom Check Correction
Every visible bar begins at zero Is the offset series included? Restore both numeric series and put offset first.
Bars end later than expected Did you plot end values as widths? Plot end minus start as duration.
A duration is negative Is the end date earlier than the start date? Correct the date or time; confirm any overnight end date.
Offsets become unexpectedly large Do the origin and starts contain the intended dates? Display full dates and correct the inputs.
Later rows use different origins Did the origin reference move during fill-down? Preserve G2’s row and column.
An unfinished task produces an error Are both endpoints present and recognized? Complete the inputs before including that row.

Do not replace formula errors with zero merely to make the chart render. Zero means a real position or a zero-length interval. Click a formula error indicator to inspect its message, as described in Apple’s Calculate values using data in table cells in Numbers on Mac.

Handle overnight tasks and optional highlighting

For an overnight task, enter the actual next-day end date and retain the same formulas. A task from November 2 at 23:00 to November 3 at 01:00 has a two-hour duration. Avoid switching to a clock-only calculation with TIMEVALUE: Apple defines that function as a fraction of a 24-hour day, which does not preserve the date difference needed here. TIMEVALUE.

Conditional highlighting can help inspect the helper table. For example, select duration cells, open Format → Cell → Conditional Highlighting → Add a Rule, and add a numeric rule for values below zero. Apple documents these rules as changing cells or their text. Treat this as a table check, not as a chart-color rule. Use cell conditions in Numbers on Mac.

Apple also states that appearance changes apply to every data point in a series, so do not expect to recolor one task bar independently within the duration series. Keep one consistent duration color for this two-series construction. Change the look of bars, wedges, and more in Numbers on Mac.

Once the three sample ranges match their expected endpoints, add tasks using the same origin and units. Fill the helper formulas into the new rows and check that the chart references include them. Preserve the start and end columns as the readable schedule, with the horizontal ranges providing a clear view of timing, duration, and overlap.

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