Errors with dates before Jan 1, 1970

[amcolash]

I think that I have some calendar events that somehow start before Jan 1, 1970 - can't say I know which of them is to blame here but I am assuming that this is a birthday. I was looking through the logs and kept seeing:

0|mm       | Error: dates lower than Thu Jan 01 1970 00:00:00 GMT-0600 (CST) are not supported
0|mm       |     at Object.toOrdinal (/home/pi/MagicMirror/node_modules/rrule-alt/lib/rrule.js:105:15)
0|mm       |     at Iterinfo.rebuild (/home/pi/MagicMirror/node_modules/rrule-alt/lib/rrule.js:1409:35)
0|mm       |     at RRule._iter (/home/pi/MagicMirror/node_modules/rrule-alt/lib/rrule.js:978:10)
0|mm       |     at RRule.between (/home/pi/MagicMirror/node_modules/rrule-alt/lib/rrule.js:794:21)
0|mm       |     at /home/pi/MagicMirror/modules/default/calendar/calendarfetcher.js:112:24
0|mm       |     at Request._callback (/home/pi/MagicMirror/modules/default/calendar/vendor/ical.js/node-ical.js:11:5)
0|mm       |     at Request.self.callback (/home/pi/MagicMirror/node_modules/request/request.js:188:22)
0|mm       |     at emitTwo (events.js:106:13)
0|mm       |     at Request.emit (events.js:191:7)
0|mm       |     at Request.<anonymous> (/home/pi/MagicMirror/node_modules/request/request.js:1171:10)

I think that we should probably gracefully change their start dates to Jan 1, 1970 (if we are not calculating ages when showing B-Days). I might have some time in the next few days to work on a PR.

[roramirez]

Here is a thing related. https://github.com/jakubroztocil/rrule/pull/125

I don't if the rrule project include this into and what kind impact can will be. Are you propose keep a rrule patched for this kind of case?

[amcolash]

Interesting. I am not sure of the impact of changing dates we try and parse. If that causes issues I think that it would be best to have a patched rrule version if that PR is not merged.

EDIT: Doing some more research into the issue, looks like JS is more than capable of dealing with dates before 1970 (since the min/max dates able to be defined are much larger than that). http://stackoverflow.com/questions/27093130/how-to-get-the-minimum-and-maximum-date

[amcolash]

I edited my local version of rrule by changing dateUtil.ORDINAL_BASE = new Date(1970, 0, 1); to dateUtil.ORDINAL_BASE = new Date(1900, 0, 1); which works for me. I am assuming that there is a better way. Without this hack however, I am not able to see some of my calendar events because rrule kills the calendar thread early.

[roramirez]

This is related with #839. Some calendar are not loaded maybe containt events before Jan 1, 1970

[tgeimer]

Thank you! changing the ORDINAL_BASE worked for me.

[nhubbard]

This issue is called epoch time. It is how Unix (and by extent, Linux) systems count time. It starts on January 1^st, 1970. This issues makes complete sense, considering that negative time doesn't exist.

[berlincount]

Sorry, but I don't think limited representability in one of the underlying formats is a good reason to not support times outside that formats range ;)

[roramirez]

@berlincount Recently I added comment here about that https://github.com/MichMich/MagicMirror/issues/839#issuecomment-296404724

[nhubbard]

@berlincount I mean, yes, JavaScript supports going before that, but it doesn't make sense unless you patch the kernel. Which is annoying and weird. In this case, you can edit the ORDINAL_BASE as said above.

[amcolash]

Seems like ruule-alt isn't much more supported than just rrule. I wonder if there are other repeating rule js libraries out there (haven't checked but might be worth it).

[MichMich]

Closed due to inactivity. Feel free to reopen.