Ruby time method conversion output result to zulu format has some discrepancy

[deepaksb2]

What is a problem?

I am using below method to convert the time to zulu format but i observed there is 3-7 seconds of time difference in conversion

Time.at(time.to_r).utc.strftime('%Y-%m-%dT%H:%M:%S.%LZ')

the time is 2025-05-12T04:40:27.452265 and after above statement the conversion is
Time Format(required): %FT%T.%N

2025-05-12T04:40:29.877Z

Can anybody help why there is few seconds difference after conversion? Is there any other way to convert time to other format?

Describe the configuration of Fluentd

Any configuration with below filter
<filter *>
@type record_modifier
remove_keys dummy

dummy ${record['convertedtimestamp'] = Time.at(time.to_r).utc.strftime('%Y-%m-%dT%H:%M:%S.%LZ')}

Describe the logs of Fluentd

There is no log error

Environment

Fluentd version:1.16.3 tried with later version as well
- TD Agent version:4.5.2 (tried with LTS version as well)
- Fluent Package version:
- Docker image (tag):
- Operating system: Windows, RHEL 8/9
- Kernel version:

[deepaksb2]

Time parsing used in regex is
(?\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}.\d+)