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+# zeitstempel
+
+[![Crates.io version](https://img.shields.io/crates/v/zeitstempel.svg?style=flat-square)](https://crates.io/crates/zeitstempel)
+[![docs.rs docs](https://img.shields.io/badge/docs-latest-blue.svg?style=flat-square)](https://docs.rs/zeitstempel)
+[![License: MPL 2.0](https://img.shields.io/github/license/badboy/zeitstempel?style=flat-square)](LICENSE)
+[![Build Status](https://img.shields.io/github/workflow/status/badboy/zeitstempel/CI?style=flat-square)](https://github.com/badboy/zeitstempel/actions?query=workflow%3ACI)
+
+zeitstempel is German for "timestamp".
+
+---
+
+Time's hard. Correct time is near impossible.
+
+This crate has one purpose: give me a timestamp as an integer, coming from a monotonic clock
+source, include time across suspend/hibernation of the host machine and let me compare it to
+other timestamps.
+
+It becomes the developer's responsibility to only compare timestamps obtained from this clock source.
+Timestamps are not comparable across operating system reboots.
+
+# Why not `std::time::Instant`?
+
+[`std::time::Instant`] fulfills some of our requirements:
+
+[`std::time::Instant`]: https://doc.rust-lang.org/1.47.0/std/time/struct.Instant.html
+
+* It's monotonic, guaranteed ([sort of][rustsource]).
+* It can be compared to other timespans.
+
+However:
+
+* It can't be serialized.
+* It's not guaranteed that the clock source it uses contains suspend/hibernation time across all operating systems.
+
+[rustsource]: https://doc.rust-lang.org/1.47.0/src/std/time.rs.html#213-237
+
+# Example
+
+```rust
+use std::{thread, time::Duration};
+
+let start = zeitstempel::now();
+thread::sleep(Duration::from_millis(2));
+
+let diff = Duration::from_nanos(zeitstempel::now() - start);
+assert!(diff >= Duration::from_millis(2));
+```
+
+# Supported operating systems
+
+We support the following operating systems:
+
+* Windows\*
+* macOS
+* Linux
+* Android
+* iOS
+
+For other operating systems there's a fallback to `std::time::Instant`,
+compared against a process-global fixed reference point.
+We don't guarantee that measured time includes time the system spends in sleep or hibernation.
+
+\* To use native Windows 10 functionality enable the `win10plus` feature. Otherwise it will use the fallback.
+
+# License
+
+MPL 2.0. See [LICENSE](LICENSE).