Per email from Missi Flavian,

 
If your team owns any of the custom must-gather images listed in our support docs[1], we need your help!
 
The workloads team has added support for `-since` and `-since-time` to `oc adm must-gather`. 
The must-gather command now (>=OCP 4.16) exports the environment variables MUST_GATHER_SINCE (a duration string)
and MUST_GATHER_SINCE_TIME (an RFC3339 compatible timestamp string) to must-gather pods.
 
The default collection plugin (openshift/must-gather[2]) was updated[3] to make use of the new env vars when collecting
pod logs (including rotated logs) and certain types of node logs.
 
We kindly request that must-gather image owners update their custom must-gather scripts to honour the new env vars.
The must-gather enhancement proposal[4] has been updated to cover the additions. 
We also kindly ask that you update the tracking sheet[5] once you add support for the new env vars.