Auto-Populating Weekly Dates in Org-Mode Tables

Here is just a quick one, I was working with an org-mode table for tracking work weeks and needed to auto-populate a Date column where each row increments by exactly one week. The table structure looked like this:

The first row has a base date (2026-01-05), and I wanted subsequent rows to automatically calculate as weekly increments: 2026-01-12, 2026-01-19, and so on.

Initially, I tried several approaches that seemed logical but encountered #ERROR results and eventually settled on a working solution which is to hardcode the base date directly in the formula:

#+TBLFM: $3='(format-time-string "%Y-%m-%d" (time-add (date-to-time "2026-01-05") (* (- @# 2) 7 24 3600)))

which gave:

and I can now of course extend the table for all the weeks in the year and I don’t have to fill in manually any more!

Here’s how it works:

• (date-to-time "2026-01-05") - Convert the hardcoded base date to Emacs time format
• (- @# 2) - Calculate the offset from the base row
• (* (- @# 2) 7 24 3600) - Convert the offset to seconds (weeks × days × hours × seconds)
• time-add - Add the offset to the base date
• format-time-string "%Y-%m-%d" - Format back to ISO date string