How to add @timestamp to records that have no time at all

Elastic Stack Logstash
1

small percentage of incoming records have no time stamp ... how do I add that time stamp to the record - to make it equal to current run time?

2

LS adds that automatically to the @timestamp field.

3

... those records are already tagged in the first part of the logstash filtering with add_tag with value "no_timestamp"

4

ok - so no need to explicitelly do that ...

5

thanks