Chrome < 71, iOS safari 13 does not have Intl.RelativeTimeFormat

[MrOrz]

iOS safari 14 works fine. However in v13:

Also for Chrome <= 70 (reported from Zenfone 4 users, chrome://version shows 70.0.3538.110)

Analysis

Cofacts browser statistics (Cofacts chatbot LIFF stats, conducted in April 2020)

Intl.RelativeTimeFormat

Supporting Chrome >= 71 only covers 90% of Android user session; and iOS does not have v14 in 2020 (when this analysis is conducted). Therefore, we should handle the case when Intl.RelativeTimeFormat is not supported.

Intl.DateTimeFormat

In Cofacts, 100% of android sessions and 99% iOS sessions have Intl.DateTimeFormat. We can safely assume Intl.DateTimeFormat always exists.

Solutions

Choose one from the following:

1. https://formatjs.io/docs/polyfills/intl-relativetimeformat/
2. Change back to date-fns
3. other polyfill