Researched about timezone management for apps

OK so this seems to be how the various packages should work on a high level:

* timezone detection - packages like jstz, moment.timezone.guess() to detect the tz of the user. These packages usually tap on the javascript Intl API
- Intl.DateTimeFormat.prototype.resolvedOptions()
* timezone library - a library of timezone offsets based on real world data (timezones are a mess, with daylight savings and all). This library would take the tz from the tx detection package, and pass on the offset needed calculate streaks
* streaks - calculate streaks data based on array of tz dates (I use date-streaks npm package)