Unknown time-zone ID: EST

[insanity13]

Kibana version:
7.5.0 Cloud

Elasticsearch version:
7.5.0 Cloud

Original install method (e.g. download page, yum, from source, etc.):
Elastic cloud

Describe the bug:
Metricbeat MSSQL does not work with EST timezone
Steps to reproduce:

1. Open Kibana Management / Advanced settings
2. Timezone for date formatting: EST
3. Open [Metricbeat MSSQL] Performance ECS Dashboard

[esaggs] > Request to Elasticsearch failed: {"error":{"root_cause":[{"type":"x_content_parse_exception","reason":"[1:89] [date_histogram] failed to parse field [time_zone]"}],"type":"x_content_parse_exception","reason":"[1:89] [date_histogram] failed to parse field [time_zone]","caused_by":{"type":"zone_rules_exception",
"reason":"Unknown time-zone ID: EST"}},"status":400}

Expected behavior:
No error, like on APM

Screenshots (if relevant):

[telune]

I came up with this exact issue while working at the feature that spurred me to open #58437, and I think there is a close relation between those issues. The reasoning is: I should not be able to set a dateFormat:tz value in Kibana that is not supported by Elasticsearch (e.g. the value EST).

Would it make sense to take this into consideration when working on a possible validator in #46717 ?

[monicaluodialpad]

We have the same issue here. Any solutions?