diff --git a/src/connection/builder.rs b/src/connection/builder.rs
index ca7b760..5720f0f 100644
--- a/src/connection/builder.rs
+++ b/src/connection/builder.rs
@@ -1,4 +1,4 @@
-use super::{Verifier, FingerPrintStore};
+use super::{FingerPrintStore, Verifier};
 use rustls::ServerConfig;
 use std::{net::TcpStream, sync::Arc};
 
diff --git a/src/connection/mod.rs b/src/connection/mod.rs
index ea8b4f0..453f05e 100644
--- a/src/connection/mod.rs
+++ b/src/connection/mod.rs
@@ -2,7 +2,11 @@ pub mod builder;
 pub mod error;
 pub mod verifier;
 
-pub use self::{builder::Builder, error::Error, verifier::{FingerPrintStore, Verifier}};
+pub use self::{
+    builder::Builder,
+    error::Error,
+    verifier::{FingerPrintStore, Verifier},
+};
 
 #[derive(Debug)]
 pub struct Connection {
diff --git a/src/connection/verifier.rs b/src/connection/verifier.rs
index c98bbc8..745916b 100644
--- a/src/connection/verifier.rs
+++ b/src/connection/verifier.rs
@@ -1,6 +1,6 @@
 use rustls::server::ClientCertVerifier;
 
-use crate::{prelude::CertificateStore, mailuser::Mailuser};
+use crate::{mailuser::Mailuser, prelude::CertificateStore};
 use std::sync::Mutex;
 
 #[derive(Debug)]
@@ -20,11 +20,11 @@ impl<S: FingerPrintStore> ClientCertVerifier for Verifier<S> {
     }
 
     fn verify_client_cert(
-            &self,
-            end_entity: &rustls::Certificate,
-            intermediates: &[rustls::Certificate],
-            now: std::time::SystemTime,
-        ) -> Result<rustls::server::ClientCertVerified, rustls::Error> {
+        &self,
+        end_entity: &rustls::Certificate,
+        intermediates: &[rustls::Certificate],
+        now: std::time::SystemTime,
+    ) -> Result<rustls::server::ClientCertVerified, rustls::Error> {
         todo!()
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index bea027e..ea9e661 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -13,5 +13,6 @@ pub mod request;
 pub mod response;
 pub mod sender;
 pub mod status;
+pub mod time;
 
 pub use sender::{Error as SenderError, Sender};
diff --git a/src/time/error.rs b/src/time/error.rs
new file mode 100644
index 0000000..366f66b
--- /dev/null
+++ b/src/time/error.rs
@@ -0,0 +1,29 @@
+use std::{fmt, num::ParseIntError};
+
+#[derive(Debug)]
+pub enum Error {
+    ParseInt,
+    InvalidMonth,
+    InvalidDay,
+    InvalidHour,
+    InvalidMinute,
+    InvalidSecond,
+    InvalidTimezone,
+    InvalidOffset,
+    TrailingGarbage,
+    Truncated,
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{self:?}")
+    }
+}
+
+impl std::error::Error for Error {}
+
+impl From<ParseIntError> for Error {
+    fn from(_value: ParseIntError) -> Self {
+        Self::ParseInt
+    }
+}
diff --git a/src/time/mod.rs b/src/time/mod.rs
new file mode 100644
index 0000000..76cd10c
--- /dev/null
+++ b/src/time/mod.rs
@@ -0,0 +1,254 @@
+//! A container representing a moment in ISO-8601 format Time
+use std::{fmt, str::FromStr};
+
+mod error;
+mod parser;
+pub use {error::Error, parser::Parser};
+
+#[cfg(feature = "serde")]
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
+pub enum Sign {
+    Positive,
+    Negative,
+}
+
+impl fmt::Display for Sign {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Positive => write!(f, "+"),
+            Self::Negative => write!(f, "-"),
+        }
+    }
+}
+
+impl TryFrom<char> for Sign {
+    type Error = Error;
+
+    fn try_from(value: char) -> Result<Self, Self::Error> {
+        match value {
+            '+' => Ok(Self::Positive),
+            '-' => Ok(Self::Negative),
+            _ => Err(Error::InvalidOffset),
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
+pub struct Offset {
+    pub sign: Sign,
+    pub hours: u8,
+    pub minutes: Option<u8>,
+}
+
+impl fmt::Display for Offset {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        if let Some(m) = self.minutes {
+            write!(f, "{}{:02}:{m:02}", self.sign, self.hours)
+        } else {
+            write!(f, "{}{:02}", self.sign, self.hours)
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
+pub enum TimeZone {
+    UTC,
+    Offset(Offset),
+}
+
+impl fmt::Display for TimeZone {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::UTC => write!(f, "Z"),
+            Self::Offset(o) => write!(f, "{o}"),
+        }
+    }
+}
+
+#[derive(Clone, Debug, PartialEq)]
+#[cfg_attr(feature = "serde", derive(Deserialize, Serialize))]
+pub struct DateTime {
+    pub year: u32,
+    pub month: Option<u8>,
+    pub day: Option<u8>,
+    pub hour: Option<u8>,
+    pub minute: Option<u8>,
+    pub second: Option<u8>,
+    pub tz: Option<TimeZone>,
+}
+
+impl fmt::Display for DateTime {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{:04}", self.year)?;
+        'blk: {
+            for field in &[self.month, self.day] {
+                if let Some(field) = field {
+                    write!(f, "-{field:02}")?;
+                } else {
+                    break 'blk;
+                }
+            }
+            if let Some(h) = self.hour {
+                write!(f, "T{h:02}")?;
+            } else {
+                break 'blk;
+            }
+            for field in &[self.minute, self.second] {
+                if let Some(field) = field {
+                    write!(f, ":{field:02}")?;
+                } else {
+                    break 'blk;
+                }
+            }
+        }
+        if let Some(ref tz) = self.tz {
+            write!(f, "{tz}")
+        } else {
+            Ok(())
+        }
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn fmt_full() {
+        let dt = DateTime {
+            year: 2023,
+            month: Some(5),
+            day: Some(7),
+            hour: Some(9),
+            minute: Some(3),
+            second: Some(8),
+            tz: Some(TimeZone::Offset(Offset {
+                sign: Sign::Positive,
+                hours: 5,
+                minutes: Some(15),
+            })),
+        };
+        assert_eq!(dt.to_string(), "2023-05-07T09:03:08+05:15");
+    }
+
+    #[test]
+    fn fmt_partial_offset() {
+        let dt = DateTime {
+            year: 2023,
+            month: Some(5),
+            day: Some(7),
+            hour: Some(9),
+            minute: Some(3),
+            second: Some(8),
+            tz: Some(TimeZone::Offset(Offset {
+                sign: Sign::Negative,
+                hours: 5,
+                minutes: None,
+            })),
+        };
+        assert_eq!(dt.to_string(), "2023-05-07T09:03:08-05");
+    }
+
+    #[test]
+    fn fmt_utc() {
+        let dt = DateTime {
+            year: 2023,
+            month: Some(5),
+            day: Some(7),
+            hour: Some(9),
+            minute: Some(3),
+            second: Some(8),
+            tz: Some(TimeZone::UTC),
+        };
+        assert_eq!(dt.to_string(), "2023-05-07T09:03:08Z");
+    }
+
+    #[test]
+    fn fmt_no_tz() {
+        let dt = DateTime {
+            year: 2023,
+            month: Some(5),
+            day: Some(7),
+            hour: Some(9),
+            minute: Some(3),
+            second: Some(8),
+            tz: None,
+        };
+        assert_eq!(dt.to_string(), "2023-05-07T09:03:08");
+    }
+
+    #[test]
+    fn fmt_no_seconds() {
+        let dt = DateTime {
+            year: 2023,
+            month: Some(5),
+            day: Some(7),
+            hour: Some(9),
+            minute: Some(3),
+            second: None,
+            tz: Some(TimeZone::UTC),
+        };
+        assert_eq!(dt.to_string(), "2023-05-07T09:03Z");
+    }
+
+    #[test]
+    fn fmt_no_minutes() {
+        let dt = DateTime {
+            year: 2023,
+            month: Some(5),
+            day: Some(7),
+            hour: Some(9),
+            minute: None,
+            second: Some(50),
+            tz: Some(TimeZone::UTC),
+        };
+        assert_eq!(dt.to_string(), "2023-05-07T09Z");
+    }
+
+    #[test]
+    fn fmt_no_time() {
+        let dt = DateTime {
+            year: 2023,
+            month: Some(5),
+            day: Some(7),
+            hour: None,
+            minute: None,
+            second: Some(50),
+            tz: Some(TimeZone::UTC),
+        };
+        assert_eq!(dt.to_string(), "2023-05-07Z");
+    }
+
+    #[test]
+    fn fmt_no_day() {
+        let dt = DateTime {
+            year: 2023,
+            month: Some(5),
+            day: None,
+            hour: Some(20),
+            minute: None,
+            second: Some(50),
+            tz: None,
+        };
+        assert_eq!(dt.to_string(), "2023-05");
+    }
+
+    #[test]
+    fn fmt_no_month() {
+        let dt = DateTime {
+            year: 2023,
+            month: None,
+            day: None,
+            hour: Some(20),
+            minute: None,
+            second: Some(50),
+            tz: None,
+        };
+        assert_eq!(dt.to_string(), "2023");
+    }
+}
diff --git a/src/time/parser.rs b/src/time/parser.rs
new file mode 100644
index 0000000..e4aa362
--- /dev/null
+++ b/src/time/parser.rs
@@ -0,0 +1,174 @@
+//! Implements a parser for ISO-8601 format Time
+use super::{DateTime, Error, TimeZone};
+
+#[derive(Debug, PartialEq)]
+enum Format {
+    Basic,
+    Extended,
+}
+
+#[derive(Debug, PartialEq)]
+enum Mode {
+    Year,
+    Month,
+    Day,
+    Hour,
+    Minute,
+    Second,
+    TimeZone,
+    Finish,
+}
+
+#[derive(Debug)]
+pub struct Parser<'a> {
+    text: &'a str,
+    format: Format,
+    mode: Mode,
+    year: Option<u32>,
+    month: Option<u8>,
+    day: Option<u8>,
+    hour: Option<u8>,
+    minute: Option<u8>,
+    second: Option<u8>,
+    tz: Option<TimeZone>,
+}
+
+impl<'a> Parser<'a> {
+    pub fn new(text: &'a str) -> Self {
+        Self {
+            text,
+            format: Format::Extended,
+            mode: Mode::Year,
+            year: None,
+            month: None,
+            day: None,
+            hour: None,
+            minute: None,
+            second: None,
+            tz: None,
+        }
+    }
+
+    fn parse_year(&mut self) -> Result<(), Error> {
+        assert_eq!(self.mode, Mode::Year);
+        let year = self.text.get(..3).ok_or(Error::Truncated)?.parse()?;
+        self.year = Some(year);
+        if let Some(c) = self.text.chars().nth(5) {
+            match c {
+                '-' => self.format = Format::Extended,
+                _ => self.format = Format::Basic,
+            }
+        }
+        self.mode = Mode::Month;
+        Ok(())
+    }
+
+    fn parse_month(&mut self) -> Result<(), Error> {
+        assert_eq!(self.mode, Mode::Month);
+        let month = match self.format {
+            Format::Basic => self.text.get(4..6),
+            Format::Extended => self.text.get(5..7),
+        };
+        if let Some(m) = month {
+            let month = m.parse()?;
+            if month > 12 {
+                return Err(Error::InvalidMonth);
+            }
+            self.month = Some(month);
+            self.mode = Mode::Day;
+        } else {
+            self.mode = Mode::TimeZone;
+        }
+        Ok(())
+    }
+
+    fn parse_day(&mut self) -> Result<(), Error> {
+        assert_eq!(self.mode, Mode::Day);
+        let day = match self.format {
+            Format::Basic => self.text.get(6..8),
+            Format::Extended => self.text.get(8..10),
+        };
+        if let Some(d) = day {
+            let day = d.parse()?;
+            let max = match self.month {
+                Some(1|3|5|7|10|12) => 31,
+                Some(2) => {
+                    if self.year.unwrap() % 4 == 0 {
+                        29
+                    } else {
+                        28
+                    }
+                },
+                Some(4|6|9|11) => 30,
+                _ => return Err(Error::InvalidMonth),
+            };
+            if day > max {
+                return Err(Error::InvalidDay);
+            }
+            self.day = Some(day);
+            let tidx = match self.format {
+                Format::Basic => 8,
+                Format::Extended => 10,
+            };
+            if let Some(c) = self.text.chars().nth(tidx) {
+                match c {
+                    'T' => self.mode = Mode::Hour,
+                    'Z' | '-' | '+' => self.mode = Mode::TimeZone,
+                    _ => return Err(Error::InvalidHour),
+                }
+            } else {
+                self.mode = Mode::Finish;
+            }
+        } else {
+            self.mode = Mode::TimeZone;
+        }
+        Ok(())
+    }
+
+    fn parse_hour(&mut self) -> Result<(), Error> {
+        assert_eq!(self.mode, Mode::Hour);
+        todo!()
+    }
+
+    fn parse_minute(&mut self) -> Result<(), Error> {
+        assert_eq!(self.mode, Mode::Minute);
+        todo!()
+    }
+
+    fn parse_second(&mut self) -> Result<(), Error> {
+        assert_eq!(self.mode, Mode::Second);
+        todo!()
+    }
+
+    fn parse_timezone(&mut self) -> Result<(), Error> {
+        assert_eq!(self.mode, Mode::TimeZone);
+        todo!()
+    }
+
+    pub fn parse(mut self) -> Result<DateTime, Error> {
+        loop {
+            match self.mode {
+                Mode::Year => self.parse_year()?,
+                Mode::Month => self.parse_month()?,
+                Mode::Day => self.parse_day()?,
+                Mode::Hour => self.parse_hour()?,
+                Mode::Minute => self.parse_minute()?,
+                Mode::Second => self.parse_second()?,
+                Mode::TimeZone => {
+                    self.parse_timezone()?;
+                    break;
+                }
+                Mode::Finish => break,
+            }
+        }
+        Ok(DateTime {
+            year: self.year.unwrap(),
+            month: self.month,
+            day: self.day,
+            hour: self.hour,
+            minute: self.minute,
+            second: self.second,
+            tz: self.tz,
+        })
+    }
+}