The Laravel queue worker is hanging on this WFM schedule sync. We’ve got a custom internal tool built on Laravel 10 using Guzzle 7.8 to push agent availability blocks into the platform. The goal is to auto-update the WFM schedule based on data from an external legacy system. The agents are based in Mexico City, so the local times need to map correctly to the platform shifts.
First, the auth token is cached in Redis, so that’s not the bottleneck. The token refreshes every 35 minutes without issue. The request hits /api/v2/wfm/schedule/agent/{agentId}. The payload structure matches the schema exactly. The code is passing the start and end timestamps in ISO 8601 format.
Here’s the logic flow. The legacy system spits out local times. The code converts everything to America/Mexico_City before sending. The Guzzle request looks like this:
$response = $client->patch("api/v2/wfm/schedule/agent/{$agentId}", [
'json' => [
'schedule' => [
'blocks' => [
[
'start' => '2023-10-27T09:00:00-06:00',
'end' => '2023-10-27T17:00:00-06:00',
'availability' => 'AVAILABLE'
]
]
]
],
'headers' => ['Authorization' => "Bearer {$token}"]
]);
The response comes back with a 400 Bad Request. The error payload points to the start field. It claims the timestamp is invalid. This is weird because the -06:00 offset is valid for Mexico City. The code is doing jack all to modify the string before the request fires. I’ve tried stripping the offset and letting the server default to UTC, but that shifts the schedule by six hours, which breaks the shift alignment.
Switching the offset to -05:00 works, but that’s the wrong timezone for the agents. The docs mention that WFM endpoints expect UTC, but the error message explicitly says “Invalid timezone offset”. The validation error is super vague. The Laravel logs show the exact string being sent. The offset is definitely there. The token has the wfm:write scope. The agent ID resolves correctly via the GET /api/v2/users endpoint first. The 400 hits on the PATCH.
The timezone offset seems to be the trigger. Removing it causes a 422 due to “Missing offset”. Adding -06:00 causes a 400 “Invalid offset”. Adding Z for UTC works, but the schedule shifts. The WFM schedule needs to show 09:00 Mexico time. Forcing Z makes it show 09:00 UTC, which is 03:00 or 04:00 local time depending on DST. The agents show up as scheduled at 3 AM.
The code tries to force the offset via Carbon:
$start = Carbon::parse($rawTime)->timezone('America/Mexico_City')->toIso8601String();
This outputs 2023-10-27T09:00:00.000000Z if I use toIso8601String() without arguments, or 2023-10-27T09:00:00-06:00 if I force it. The latter breaks the API. The former works but breaks the time. The Guzzle request throws the exception immediately. No retry logic kicks in because the 400 is treated as a client error. The loop stops. The queue job fails after three attempts. The error handler dumps the payload.
{
"request": "PATCH /api/v2/wfm/schedule/agent/5a1b2c3d-4e5f-6g7h-8i9j-0k1l2m3n4o5p",
"payload": {
"schedule": {
"blocks": [
{
"start": "2023-10-27T09:00:00-06:00",
"end": "2023-10-27T17:00:00-06:00",
"availability": "AVAILABLE"
}
]
}
},
"status": 400,
"error": "Invalid input: start"
}
The platform seems to hate the -06:00 string. Is there a way to pass the timezone explicitly in the header, or does the WFM API strictly require UTC with a separate timezone field in the JSON body? The schema docs for WFM are thin on this. The generic schedule endpoint doesn’t mention timezone handling. The payload structure remains identical to the working UTC version, just the offset changes. The error persists. The queue is filling up with failed jobs. The agents are missing their schedules for tomorrow. The code is stuck on this offset validation.