vault/Technical/Emacs/Emacs Calendar.md

For the config, see Emacs Config for the Source of truth

Config:

(require 'org-caldav)
(require 'url)
(require 'icalendar)
(modify-coding-system-alist 'file "caldav-work\\.org\\'" 'utf-8-unix)
(setq org-icalendar-timezone "Europe/London")
(setq calendar-time-zone 60) ;; minutes offset from UTC (BST = +60)
(setq calendar-standard-time-zone-name "GMT")
(setq calendar-daylight-time-zone-name "BST")
(setq org-caldav-timezone "Europe/London")
(defvar my/outlook-ics-url
  "https://outlook.office365.com/owa/calendar/b910ea835e414663831e505f3d10baa2@microlise.com/d2568a0134fb49af92d39c1669c4729317662288011094411305/calendar.ics")

(defvar my/outlook-org-file
  "D:\\_nextcloud\\master-folder\\org_files\\calendar\\caldav-work.org")

(defvar my/ics-python-script
  "D:\\_nextcloud\\master-folder\\org_files\\calendar\\ics_to_org.py")

(defun my/sync-outlook-calendar ()
  "Fetch and expand Outlook ICS (including recurrences) into org file."
  (interactive)
  (message "Syncing Outlook calendar...")
  (let* ((cmd (format "python \"%s\" \"%s\" \"%s\""
                      my/ics-python-script
                      my/outlook-ics-url
                      my/outlook-org-file))
         (result (shell-command-to-string cmd)))
    (message "Outlook calendar sync: %s" (string-trim result))))

;; Sync on startup and every 30 minutes
(my/sync-outlook-calendar)
(run-with-timer (* 30 60) (* 30 60) #'my/sync-outlook-calendar)
;; --- CalDAV for native Nextcloud calendars ---
(setq org-caldav-url "https://nextcloud.zainezq.com/remote.php/dav/calendars/zaine/")
(setq org-caldav-calendars
      '((:calendar-id "personal"
            :inbox "D:\\_nextcloud\\master-folder\\org_files\\calendar\\caldav-personal.org"
            :files nil)
  (:calendar-id "zxh"
            :inbox "D:\\_nextcloud\\master-folder\\org_files\\calendar\\caldav-family.org"
            :files nil)))

;; --- Agenda files ---
(setq org-agenda-files
      '("D:\\_nextcloud\\master-folder\\org_files\\calendar\\caldav-personal.org"
  "D:\\_nextcloud\\master-folder\\org_files\\calendar\\caldav-work.org"
  "D:\\_nextcloud\\master-folder\\org_files\\calendar\\caldav-family.org"
  "D:\\_nextcloud\\master-folder\\org_files\\org_roam\\Books\\20250724230557-books_org_agenda.org"))

Explanation:

• This configuration sets up Emacs to sync with both a Nextcloud calendar (via CalDAV) and an Outlook calendar (via ICS). It uses a Python script to fetch and convert the Outlook ICS data into an org file format that Emacs can read. The Nextcloud calendar is synced directly using the org-caldav package. Both calendars are included in the org-agenda files, so that I can view all events in one place. The sync for the Outlook calendar runs every 30 minutes to keep it up to date.
• To sync the Outlook calendar, you call the my/sync-outlook-calendar function, which runs the Python script to fetch and convert the ICS data. The Nextcloud calendar is synced automatically by org-caldav whenever you open Emacs or refresh the calendar.