Jacob•2w ago

cron: a schedule should have a next event: InvalidTime

Hi, I'm not sure this is the right place to report this, but hopefully it reaches the right people. We noticed some schedules failing during the transition to "winter" time, the night between 25 and 26 October. Since Windmill has been stable both before and after the switch from daylight savings I believe it might be related to rewinding the clock. - Windmill version: CE v1.476.0-2-g09f4ee22b - Worker logs are attached - The error is consistent in the sense that all our schedules for the range of time close to 00:00 the 26:th failed with the same error. All our workers were affected - I'm not sure the flow is relevant since this error affects all our flows. But if I'm wrong just tell me and I'll provide one - The infra is based on docker compose, three workers. The setup is simple, all on the same machine with 100GB storage, 32GB RAM, 8 vCPUs. The actual error seems to be:

thread 'tokio-runtime-worker' panicked at windmill-common/src/utils.rs:489:18:
cron: a schedule should have a next event: InvalidTime
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
2025-10-25T23:45:00.054861Z  INFO windmill-api/src/lib.rs:625: Graceful shutdown of server
Error: task 102 panicked with message "cron: a schedule should have a next event: InvalidTime"
jemalloc enabled
Connecting to database...
OTEL settings loaded: tracing (false), logs (false), metrics (false), endpoint (None), headers defined: (false)

thread 'tokio-runtime-worker' panicked at windmill-common/src/utils.rs:489:18:
cron: a schedule should have a next event: InvalidTime
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
2025-10-25T23:45:00.054861Z  INFO windmill-api/src/lib.rs:625: Graceful shutdown of server
Error: task 102 panicked with message "cron: a schedule should have a next event: InvalidTime"
jemalloc enabled
Connecting to database...
OTEL settings loaded: tracing (false), logs (false), metrics (false), endpoint (None), headers defined: (false)

Any ideas on how we can avoid this?

wm-worker.log

2 Replies

rubenf•2w ago

I think it's better handled in more recent releases as there was a fix in the cron library we use

JacobOP•2w ago

Alright, we'll attempt an upgrade before next time then and see.

cron: a schedule should have a next event: InvalidTime

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