[Bug] Calendar module fails with "Cannot read properties of undefined (reading 'guess')" in v2.34.0

[amarand]

Environment

MagicMirror² version: 2.34.0
Node version: v22.21.1
npm version: 10.9.4; pm2: 5.x
Platform: Raspberry Pi 5 running Raspberry Pi OS (Trixie/Debian 13)

Which start option are you using?

node --run start

Are you using PM2?

Yes

Module

calendar

Have you tried disabling other modules?

• Yes
• No

Have you searched if someone else has already reported the issue on the forum or in the issues?

• Yes

What did you do?

1. Installed MagicMirror v2.34.0 fresh on Raspberry Pi 5 (Trixie)
2. Configured the calendar module with CalendarLabs US Holidays feed:

   {
     module: "calendar",
     header: "US Holidays",
     position: "top_left",
     config: {
       calendars: [
         {
           symbol: "calendar-check",
           url: "https://www.calendarlabs.com/ical-calendar/ics/76/US_Holidays.ics"
         }
       ],
       fade: false
     }
   }

3. Started MagicMirror with PM2
4. Calendar module displayed error message instead of events

What did you expect to happen?

The calendar module should display upcoming US holidays from the iCal feed. This same configuration worked correctly in MagicMirror v2.31.0 (tested same morning before upgrade).

What actually happened?

Calendar module shows error: "Error in the calendar module. Check logs for more details."

Console shows:

[ERROR] [calendar] Calendar Error. Could not fetch calendar: https://www.calendarlabs.com/ical-calendar/ics/76/US_Holidays.ics TypeError: Cannot read properties of undefined (reading 'guess')
    at Object.calculateTimezoneAdjustment (/home/sgoodman/MagicMirror/modules/default/calendar/calendarfetcherutils.js:24:31)

Additional comments

Root Cause

In modules/default/calendar/calendarfetcherutils.js, line 5 imports moment:

const moment = require("moment");

However, line 24 calls moment.tz.guess() which requires the moment-timezone library:

event.start.tz = moment.tz.guess();

Since moment-timezone is not imported, moment.tz is undefined, causing the error.

Proposed Fix

Change line 5 in modules/default/calendar/calendarfetcherutils.js from:

const moment = require("moment");

To:

const moment = require("moment-timezone");

I've tested this fix locally and it resolves the issue completely. The calendar module now loads and displays events correctly.

Participation

• I am willing to submit a pull request for this change.

[sdetweil]

There is a comprehensive set of changes in the next release to do away with moment.

Please download and test with the develop branch

[amarand]

There is a comprehensive set of changes in the next release to do away with moment.

Please download and test with the develop branch

Sorry! I had to do a fresh clone to see the develop branch. After checking it out, the modules/ directory appears to be empty—no default modules present.

Should I be testing a specific commit, or is this branch still being prepared?

(Edit: ahh, defaultmodules...huge rewrite of MM. I'm fiddling. Thank you!)

[sdetweil]

From the topic on the forums

If you did manual install

cd ~/MagicMirror
git checkout develop
git pull
npm install
restart MagicMirror as normal

if you used my install script

cd ~/MagicMirror
git fetch origin develop:develop
git checkout develop
npm install
if u are already ON the develop branch, and want to update to the latest,

git pull
npm install
restart MagicMirror as normal

[amarand]

There is a comprehensive set of changes in the next release to do away with moment.

Please download and test with the develop branch

I'm on the develop branch, and yes, that's been resolved. Thank you! Should we close this bug as resolved in develop?

[amarand]

cd ~/MagicMirror git fetch origin develop:develop git checkout develop npm install if u are already ON the develop branch, and want to update to the latest,

Ahh okay. I'm just used to using the latest release. We're good.

$ grep '"version"' package.json
"version": "2.35.0-develop",

Thank you for the quick response!

[khassel]

I'm on the develop branch, and yes, that's been resolved. Thank you! Should we close this bug as resolved in develop?

can left open so others see it, will be closed with next release