Assuming Prefect 3.x, you’ve got two good options: 1) Cron (6 fields; seconds first) - Expression:

5 * * * * *

→ runs at the 5th second of every minute - CLI:

prefect deployment schedule create <deployment-name> --cron "5 * * * * *" --timezone "UTC"

- Python:

from prefect import flow
from prefect.schedules import Cron

@flow
def my_flow():
    ...

my_flow.serve(
    name="every-minute-at-5s",
    schedule=Cron("5 * * * * *", timezone="UTC")
)

2) RRule (explicit seconds) - Expression:

FREQ=MINUTELY;BYSECOND=5

- CLI:

prefect deployment schedule create <deployment-name> --rrule "FREQ=MINUTELY;BYSECOND=5" --timezone "UTC"

- Python:

from prefect import flow
from prefect.schedules import RRule

@flow
def my_flow():
    ...

my_flow.serve(
    name="every-minute-at-5s",
    schedule=RRule("FREQ=MINUTELY;BYSECOND=5", timezone="UTC")
)

Notes: - With cron in Prefect (via croniter), the 6-field format is “second minute hour day month day_of_week”, so

5 * * * * *

means “at second 5 of every minute.” - Add

--timezone

(or

timezone=

in Python) if you need a specific TZ. Do you already have a deployment created, or would you like an example using

flow.from_source(...).deploy(...)

with schedules?