Use explicit units in time delta

What's Changed

• Use black, isort, ruff, pre-commit by @jzuhone in #59
• Use explicit time units in time delta by @taldcroft in #61
• fix ruff, black, gitignore by @jzuhone in #62

Full Changelog: 4.5.0...4.5.2

Includes the following merges:

• PR #62: fix ruff, black, gitignore
• PR #61: Use explicit time units in time delta
• PR #59: Use black, isort, ruff, pre-commit