GreenGrass logging format of date time

Question

does anyone know what the date/time format is called that is used in greengrass

the **2022-06-15T08:26:23.770Z** in for example /greengrass/v2/logs/greengrass.log

**2022-06-15T08:26:23.770Z** [INFO] (Thread-5) com.aws.greengrass.shadowmanager.ipc.UpdateThingShadowRequestHandler: Successfully updated shadow. {service-name=au.com.blabla.gg_shadow_config, thing name=smartdvr-1423019132001, shadow name=config1, local-version=20102}

I'm trying to match the greengrass log format using normal python `logging.Formatter` for some non-greengrass related logfiles, but use 1 logfile_upload component to do one-shot logfile request,response to CloudWatch, and it would be easier if they are all in the same format.

```
logging.Formatter.formatTime = (lambda self, record, datefmt=None: datetime.datetime.fromtimestamp(record.created, datetime.timezone.utc).astimezone().isoformat(sep="T",timespec="milliseconds"))

```

gets very close
`2021-08-05T22:43:02.985614+00:00 Something logged here
`
but **+00:00** needs to be replaced with **Z**

https://en.wikipedia.org/wiki/ISO_8601 describes both the +00:00 and the Z , so it doesn't help me with finding examples

Accepted Answer

```
fh = RotatingFileHandler('/data/logs/gg_upload_logs.log', maxBytes=80000, backupCount=4)
formatter = logging.Formatter( fmt='%(asctime)s.%(msecs)03dZ %(message)s', datefmt='%Y-%m-%dT%H:%M:%S')
fh.setFormatter(formatter)
```

GreenGrass logging format of date time

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