[Bugfix] Wrong ISO time format in Python quickstart for Calendar API

[Marc416]

Hi team,

issue #2115

While testing the Calendar API using the Python quickstart guide, I noticed an issue in the time formatting line.

The current code is:

now = datetime.datetime.now(tz=datetime.timezone.utc).isoformat() + "Z"  # 'Z' indicates UTC time

However, this results in an invalid ISO 8601 timestamp like:

makefile

2025-04-07T14:39:12.345678+00:00Z

Appending "Z" after a timezone-aware ISO string (which already includes +00:00) makes the timestamp invalid. This can cause unexpected errors when calling the API.

It should be corrected to:

now = datetime.datetime.now(tz=datetime.timezone.utc).isoformat()

When the incorrect format is used, it leads to errors like this:

{
  "error": {
    "code": 403,
    "message": "Method doesn't allow unregistered callers (callers without established identity)...",
    "status": "PERMISSION_DENIED"
  }
}

Thanks!

[google-cla]

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[Marc416]

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

Thank you for info me.
I registered with CLA.

[Marc416]

check this
#2117