Check if a Timestamp Falls in a Daily Maintenance Window in Python

A small Python function that returns True when a datetime falls inside a daily maintenance window, and a demo printing yes/no for sample timestamps.

Easy Python 3.9+ Aug 9, 2026 Observability & SRE 15 views 0 copies

maintenance datetime scheduling observability

Python code

22 lines
Python 3.9+
Run it 
from datetime import datetime, timedelta
from zoneinfo import ZoneInfo


def in_maintenance_window(now: datetime, start_hour: int = 2, duration_hours: int = 4) -> bool:
    """Return True if 'now' falls inside the daily maintenance window."""
    day_start = now.replace(hour=start_hour, minute=0, second=0, microsecond=0)
    window_end = day_start + timedelta(hours=duration_hours)
    return day_start <= now < window_end


if __name__ == "__main__":
    fmt = "%Y-%m-%d %H:%M"
    tests = [
        datetime.fromisoformat("2025-07-10T01:30:00"),
        datetime.fromisoformat("2025-07-10T02:30:00"),
        datetime.fromisoformat("2025-07-10T05:59:00"),
        datetime.fromisoformat("2025-07-10T06:00:00"),
    ]

    for ts in tests:
        print(f"{ts.strftime(fmt)} -> maintenance={'yes' if in_maintenance_window(ts) else 'no'}")

Output

stdout 
2025-07-10 01:30 -> maintenance=no
2025-07-10 02:30 -> maintenance=yes
2025-07-10 05:59 -> maintenance=yes
2025-07-10 06:00 -> maintenance=no

How it works

The in_maintenance_window function builds a naive datetime for the start of the window on the same day as now by calling replace(hour=start_hour, ...). The end is calculated by adding a timedelta, and membership is tested with day_start <= now < window_end, which correctly excludes the exact end time. All values stay naive, so the comparison works directly on local system time; for production you would pass timezone-aware datetimes instead. The demo prints the result for four timestamps around the window boundaries to show inclusive start and exclusive end behavior.

Common mistakes

  • Using `<= window_end` instead of `< window_end`, which includes the exact end time.
  • Forgetting to reset minutes/seconds/microseconds, leading to an off-by-a-few-seconds window.
  • Handling naive datetimes in mixed timezone contexts without first converting to a single timezone.

Variations

  1. Return the start and end datetimes as a tuple instead of a boolean.
  2. Support overlapping midnight windows by adding a day when the end hour is less than the start hour.

Real-world use cases

  • Gate automated deploys or batch jobs so they don't run during a planned database maintenance window.
  • Suppress paging alerts for known maintenance periods to reduce alert fatigue.
  • Decide when to run expensive cleanup in a scheduler based on the current wall-clock time.

Sponsored

Run this sample

Open the browser IDE to tweak the example and see results without installing anything.

Open editor

More from Observability & SRE

Keep learning

Related tutorials and quizzes for this topic.

Tutorials

Quizzes