Should we support epoch_seconds?

[nik9000]

Should we support epoch_seconds to be consistent with epoch_millis?

elasticsearch/server/src/main/java/org/elasticsearch/common/time/FormatNames.java

Lines 56 to 57 in a92a647

	EPOCH_SECOND("epoch_second"),
	EPOCH_MILLIS("epoch_millis"),

The inconsistency upsets me a little....

[elasticmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)

[pgomulka]

++ to this, we could deprecate this format in 7.x and have it consistent in 8.0

[pgomulka]

we discussed this on core infra sync on 21April
We concluded that we will add epoch_seconds in addition to epoch_second in version 7 and 8
However we will not plan on removing epoch_second soon-ish. It has to stay until version 9 at minimum, because of index backwards compatibility.
Users should be creating new indicies with epoch_seconds, and epoch_second will be deprecated.
We hope that epoch_second will get stale and not used thanks to data retention - indices created with that format will be removed by users themself.