Moment-timezone: Parse date using timezone return different values based on format

[MCFreddie777]

Parsing date using timezone returns different output if used with and without date format.

Current result:

moment.tz("18 Oct 2019, 15:40:42", "Europe/London").valueOf()
1571413242000
moment.tz("18 Oct 2019, 15:40:42", "DD MMM YYYY, hh:mm:ss", "Europe/London").valueOf()
1571409642000

Expected result:

moment.tz("18 Oct 2019, 15:40:42", "Europe/London").valueOf()
1571409642000
moment.tz("18 Oct 2019, 15:40:42", "DD MMM YYYY, hh:mm:ss", "Europe/London").valueOf()
1571409642000

This does not look like expected behaviour.
Result of converting date based on timezone should not be dependent on date formatting.

[thiagozampieri]

The problem is that moment-timezone only accepts auto parse for RFC2822 or ISO format.

var moment1 = moment.tz("2019-10-18T15:40:42", "America/New_York").valueOf();
var moment2 = moment.tz("18 Oct 2019, 15:40:42", "DD MMM YYYY, hh:mm:ss", "America/New_York").valueOf();

[ellenaua]

This is the same bug as https://github.com/moment/moment-timezone/issues/807 - @todo fix it