Highlight overdue tasks in FileMaker with conditional formatting

1. Define overdue before choosing a color

For this exercise, a task is overdue when it has a due date earlier than today and its status is neither Done nor Cancelled. A task due today is not overdue. A task with no due date needs a different cue. Write that rule down first so the visual design has a clear meaning.

Use a practice Tasks table with TaskName (Text), DueDate (Date) and Status (Text). Keep status spelling consistent. If your app uses Completed instead of Done, adapt the rule deliberately; do not paste a formula that assumes another app’s values.

2. Create a small test set

Enter actual dates relative to the day you test; do not type the word Yesterday into the Date field. This six-record set is more useful than making every example late: it checks the exclusions as well as the positive case.

3. Apply one rule to one object

In Layout mode, select the task-name field object. Choose Format → Conditional, add a condition and choose the formula-based option. Use the expression below, changing the table occurrence and field names to match your practice file. This is a layout condition, not a stored calculation field or a script.

/*
	Purpose: Flag dated, overdue tasks that are neither done nor cancelled.
	Author: Plato
	Created Date: 2026-10-10
*/

not IsEmpty ( Tasks::DueDate )
and Tasks::DueDate < Get ( CurrentDate )
and Tasks::Status ≠ "Done"
and Tasks::Status ≠ "Cancelled"

Choose a pale warning fill and dark text that remain readable together. Return to Browse mode and inspect all six records. Conditional formatting changes presentation, not the stored due date or status. See the Claris conditional-formatting instructions.

4. Make the meaning visible without color

Keep the due date and status next to the task name. A person should be able to understand the warning from those values even if they cannot distinguish the fill color. If you later add a calculated “Overdue” label or a warning icon, test that it follows the same rule. An icon alone should not be the only explanation.

Avoid applying red to every field in a row. One consistent cue often makes the important item easier to find. Preview the layout in grayscale or on a low-contrast display and ask whether the date and status still explain the situation.

If the selected field looks different while being edited, compare its object state and other formatting rules. Do not keep adding conditions until the appearance happens to look right.

5. Check boundary cases and context

• If completed tasks are still highlighted, compare the actual stored status with the word in the formula.
• If every row in a portal has the same result, inspect the table occurrence referenced by the condition. It should identify the row’s task, not an unrelated parent task.
• If a blank date highlights, check that the non-empty test is present.
• If the window stays open overnight, refresh or revisit the layout and check the new day’s results; do not assume a color will repaint at midnight by itself.

Only after the single object works should you apply the pattern elsewhere. Existing objects may already have their own conditions, so review their rules before replacing formatting.

6. Change the data and predict the result

Mark Send draft as Done: its warning should disappear when the display refreshes. Reopen it as Open: it should become overdue again. Give Plan next call tomorrow’s date: it should remain unhighlighted. Move that date to yesterday: it should highlight.

Finished result: exactly one overdue task in the original six-row test set, with a warning that follows data changes. This rule is an interface aid, not a reminder service or an automatic escalation workflow.

References

• Conditional formatting

Use a practice copy and verify the result in your FileMaker version. Menu wording and platform behavior may differ.