Clarifying the serialization of a `SystemTime`
@@ -26,6 +26,13 @@ use crypto::{Hash, PublicKey, HASH_SIZE, PUBLIC_KEY_LENGTH};
/// will not sort signed integer types in the natural order; therefore, they are
/// mapped to the corresponding unsigned type by adding a constant to the source value.
///
+/// The `SystemTime` (de)serialization is only possible for the values greater than
+/// 1970-01-01 00:00:00 UTC. Since the `SystemTime` type saves time in the form
+/// `(seconds: u64, nanoseconds: u32)`, the total occupied size of `SystemTime` in the storage
+/// is 12 bytes, the time is stored as a buffer of bytes `buffer[0..12]: &[u8]`.
+/// Accordingly, the seconds are stored as a buffer of bytes `buffer[0..8]: &[u8]`,
+/// the nanoseconds - `buffer[8..12]: &[u8]`.
+///
/// # Examples
///
/// ```
