///

You can see the **FastAPI Experts** for:

* [Last Month](#fastapi-experts-last-month) 🤓
* [3 Months](#fastapi-experts-3-months) 😎
* [6 Months](#fastapi-experts-6-months) 🧐
* [1 Year](#fastapi-experts-1-year) 🧑‍🔬
* [**All Time**](#fastapi-experts-all-time) 🧙

### FastAPI Experts - Last Month

			return 0, nil
		case false:
			return -1, nil
		}
	}

	// Try to parse as a number of months
	if !strings.HasSuffix(s, "m") {
		return -1, errors.New("unknown format")
	}

	months, err := strconv.Atoi(strings.TrimSuffix(s, "m"))
	if err != nil {
		return -1, err
	}

	if months < minimumBitrotCycleInMonths {
		return -1, fmt.Errorf("minimum bitrot cycle is %d month(s)", minimumBitrotCycleInMonths)

	}
	return FromTimestamp(t.Add(duration)), nil
}

// dateDiff computes the difference between two times in terms of the
// `timePart` which can be years, months, days, hours, minutes or
// seconds. For difference in years, months or days, the time part,
// including timezone is ignored.
func dateDiff(timePart string, ts1, ts2 time.Time) (*Value, error) {
	if ts2.Before(ts1) {

		// Testcase index 20
		{30 * 24 * time.Hour, "my_download_url", "1 month before the latest release"},
		{31 * 24 * time.Hour, "my_download_url", "1 month before the latest release"},
		{61 * 24 * time.Hour, "my_download_url", "2 months before the latest release"},
		{360 * 24 * time.Hour, "my_download_url", "1 year before the latest release"},
		{361 * 24 * time.Hour, "my_download_url", "1 year before the latest release"},

For example, it was clear that ideally it should be based on standard Python type hints.

Also, the best approach was to use already existing standards.

So, before even starting to code **FastAPI**, I spent several months studying the specs for OpenAPI, JSON Schema, OAuth2, etc. Understanding their relationship, overlap, and differences.

## Design { #design }