Datum Plot 0.3.11

Dates and times.

Dates in tables

• The X column of an XY table can hold dates or dates and times: right-click its heading and choose how they are shown (5 Nov 2026, 05-Nov-26, 2026-11-05, 05/11/2026 or Nov 2026). Nothing changes for tables you leave as numbers, and older files open as before.
• Type or paste dates in many forms: 2026-11-05, 2026-11-05 14:30, 5-Nov-26, 5 Nov 2026, Nov 5, 2026, 05/11/2026; impossible dates (31 Feb) are refused. File › Options › Dates sets whether 05/11/2026 is day first or month first (the first time, from your system's language).
• Dates are kept as numbers, days since 1 January 1970, so everything else works on them unchanged.

Dates on graphs

• A date X axis with automatic ticks (the year once, then months or days), or day and month, month and year, ISO or week numbers (Format Graph › X Axis), with the range typed as dates. Hovering shows the date, and every export keeps the date ticks.

Analyses and exports

• Straight-line fits on dates give the slope per day. Workbook exports (.xlsx, .ods) write real dates.

From Datum Plan

• Datum Plot 0.3.11 is the first version that opens Datum Plan's time charts with dates (xFormat: "date", days since 1970): they open on a date axis with no questions asked.

New sample

• Readings over time: weekly dissolved oxygen at two river sites, on a date axis, with the fall per day.