diff --git a/src/eventlist/event/date.rs b/src/eventlist/event/date.rs
new file mode 100644
index 0000000..6ccd462
--- /dev/null
+++ b/src/eventlist/event/date.rs
@@ -0,0 +1,53 @@
+/*
+   TU - Time's Up!
+   Copyright (C) 2020  Julio Biason
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+use chrono::prelude::*;
+use chrono::DateTime;
+use serde_derive::Deserialize;
+use serde_derive::Serialize;
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Date {
+    year: i32,
+    month: u32,
+    day: u32,
+}
+
+impl From<&DateTime<Local>> for Date {
+    fn from(origin: &DateTime<Local>) -> Date {
+        Date {
+            year: origin.year(),
+            month: origin.month(),
+            day: origin.day(),
+        }
+    }
+}
+
+impl Date {
+    pub fn year(&self) -> i32 {
+        self.year
+    }
+
+    pub fn month(&self) -> u32 {
+        self.month
+    }
+
+    pub fn day(&self) -> u32 {
+        self.day
+    }
+}
diff --git a/src/eventlist/event/eventtype.rs b/src/eventlist/event/eventtype.rs
new file mode 100644
index 0000000..b9c1faf
--- /dev/null
+++ b/src/eventlist/event/eventtype.rs
@@ -0,0 +1,61 @@
+/*
+   TU - Time's Up!
+   Copyright (C) 2020  Julio Biason
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+use chrono::prelude::*;
+use chrono::DateTime;
+use serde_derive::Deserialize;
+use serde_derive::Serialize;
+
+use crate::eventlist::event::date;
+use crate::eventlist::event::time;
+
+#[derive(Serialize, Deserialize, Debug)]
+#[serde(tag = "due", content = "datetime")]
+pub enum EventType {
+    AllDay(date::Date),
+    AtTime(date::Date, time::Time),
+}
+
+impl From<&EventType> for DateTime<Local> {
+    fn from(origin: &EventType) -> Self {
+        match origin {
+            EventType::AllDay(d) => Local.ymd(d.year(), d.month(), d.day()).and_hms(23, 59, 59),
+            EventType::AtTime(d, t) => {
+                Local
+                    .ymd(d.year(), d.month(), d.day())
+                    .and_hms(t.hour(), t.minute(), 59)
+            }
+        }
+    }
+}
+
+impl From<&EventType> for String {
+    fn from(origin: &EventType) -> String {
+        match origin {
+            EventType::AllDay(d) => format!("{}{}{}0000", d.year(), d.month(), d.day()),
+            EventType::AtTime(d, t) => format!(
+                "{}{}{}{}{}",
+                d.year(),
+                d.month(),
+                d.day(),
+                t.hour(),
+                t.minute()
+            ),
+        }
+    }
+}
diff --git a/src/eventlist/event.rs b/src/eventlist/event/mod.rs
similarity index 52%
rename from src/eventlist/event.rs
rename to src/eventlist/event/mod.rs
index 143468a..aeb779c 100644
--- a/src/eventlist/event.rs
+++ b/src/eventlist/event/mod.rs
@@ -25,74 +25,21 @@ use serde_derive::Deserialize;
 use serde_derive::Serialize;
 use uuid::Uuid;
 
-static DATE_FORMAT: &str = "%Y-%m-%d %H:%M:%S";
-
-#[derive(Serialize, Deserialize, Debug)]
-pub struct Date {
-    year: i32,
-    month: u32,
-    day: u32,
-}
-
-impl From<&DateTime<Local>> for Date {
-    fn from(origin: &DateTime<Local>) -> Date {
-        Date {
-            year: origin.year(),
-            month: origin.month(),
-            day: origin.day(),
-        }
-    }
-}
-
-#[derive(Serialize, Deserialize, Debug)]
-pub struct Time {
-    hour: u32,
-    min: u32,
-}
+mod date;
+mod eventtype;
+mod time;
 
-impl From<&DateTime<Local>> for Time {
-    fn from(origin: &DateTime<Local>) -> Time {
-        Time {
-            hour: origin.hour(),
-            min: origin.minute(),
-        }
-    }
-}
-
-#[derive(Serialize, Deserialize, Debug)]
-#[serde(tag = "due", content = "datetime")]
-pub enum EventDateType {
-    AllDay(Date),
-    AtTime(Date, Time),
-}
-
-impl From<&EventDateType> for DateTime<Local> {
-    fn from(origin: &EventDateType) -> Self {
-        match origin {
-            EventDateType::AllDay(d) => Local.ymd(d.year, d.month, d.day).and_hms(0, 0, 0),
-            EventDateType::AtTime(d, t) => {
-                Local.ymd(d.year, d.month, d.day).and_hms(t.hour, t.min, 0)
-            }
-        }
-    }
-}
+use date::Date as EventDate;
+use eventtype::EventType;
+use time::Time as EventTime;
 
-impl From<&EventDateType> for String {
-    fn from(origin: &EventDateType) -> String {
-        match origin {
-            EventDateType::AllDay(d) => format!("{}{}{}0000", d.year, d.month, d.day),
-            EventDateType::AtTime(d, t) => {
-                format!("{}{}{}{}{}", d.year, d.month, d.day, t.hour, t.min)
-            }
-        }
-    }
-}
+static DATE_FORMAT: &str = "%Y-%m-%d %H:%M:%S";
 
 #[derive(Serialize, Deserialize, Debug)]
 pub struct Event {
     pub id: String,
     pub description: String,
-    due: EventDateType,
+    due: EventType,
 }
 
 fn uuid() -> String {
@@ -100,32 +47,46 @@ fn uuid() -> String {
     format!("{:x}", id)
 }
 
+#[derive(Debug)]
+pub enum EventError {
+    InvalidDate(String),
+    TooOld,
+}
+
+impl From<chrono::format::ParseError> for EventError {
+    fn from(error: chrono::format::ParseError) -> EventError {
+        EventError::InvalidDate(error.to_string())
+    }
+}
+
 impl Event {
-    // TODO result this
-    pub fn new_on_date(description: &str, date: &str) -> Self {
+    pub fn new_on_date(description: &str, date: &str) -> Result<Self, EventError> {
         let fake_datetime = format!("{} 00:00:00", date);
-        if let Ok(dt) = Local.datetime_from_str(&fake_datetime, DATE_FORMAT) {
-            // TODO turn format into static
-            Self {
+        let dt = Local.datetime_from_str(&fake_datetime, DATE_FORMAT)?;
+
+        if dt < Local::now() {
+            Err(EventError::TooOld)
+        } else {
+            Ok(Self {
                 id: uuid(),
                 description: description.into(),
-                due: EventDateType::AllDay(Date::from(&dt)),
-            }
-        } else {
-            panic!("Failed to parse the date");
+                due: EventType::AllDay(EventDate::from(&dt)),
+            })
         }
     }
 
-    pub fn new_on_date_time(description: &str, date: &str, time: &str) -> Self {
+    pub fn new_on_date_time(description: &str, date: &str, time: &str) -> Result<Self, EventError> {
         let fake_datetime = format!("{} {}:00", date, time);
-        if let Ok(dt) = Local.datetime_from_str(&fake_datetime, DATE_FORMAT) {
-            Self {
+        let dt = Local.datetime_from_str(&fake_datetime, DATE_FORMAT)?;
+
+        if dt < Local::now() {
+            Err(EventError::TooOld)
+        } else {
+            Ok(Self {
                 id: uuid(),
                 description: description.into(),
-                due: EventDateType::AtTime(Date::from(&dt), Time::from(&dt)),
-            }
-        } else {
-            panic!("Failed to parse the date");
+                due: EventType::AtTime(EventDate::from(&dt), EventTime::from(&dt)),
+            })
         }
     }
 
@@ -136,15 +97,11 @@ impl Event {
         log::debug!("ETA for {}: {}", self.id, eta.num_minutes());
 
         match self.due {
-            EventDateType::AllDay(_) if eta.num_minutes() > 0 => {
-                Some(format!("{}d", eta.num_days()))
-            }
-            EventDateType::AtTime(_, _) if eta.num_days() > 0 => {
+            EventType::AllDay(_) if eta.num_minutes() > 0 => Some(format!("{}d", eta.num_days())),
+            EventType::AtTime(_, _) if eta.num_days() > 0 => {
                 Some(format!("{}d {}h", eta.num_days(), eta.num_hours()))
             }
-            EventDateType::AtTime(_, _) if eta.num_hours() > 0 => {
-                Some(format!("{}h", eta.num_hours()))
-            }
+            EventType::AtTime(_, _) if eta.num_hours() > 0 => Some(format!("{}h", eta.num_hours())),
             _ => None,
         }
     }
diff --git a/src/eventlist/event/time.rs b/src/eventlist/event/time.rs
new file mode 100644
index 0000000..ce9a0a5
--- /dev/null
+++ b/src/eventlist/event/time.rs
@@ -0,0 +1,47 @@
+/*
+   TU - Time's Up!
+   Copyright (C) 2020  Julio Biason
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+
+use chrono::prelude::*;
+use chrono::DateTime;
+use serde_derive::Deserialize;
+use serde_derive::Serialize;
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct Time {
+    hour: u32,
+    min: u32,
+}
+
+impl From<&DateTime<Local>> for Time {
+    fn from(origin: &DateTime<Local>) -> Time {
+        Time {
+            hour: origin.hour(),
+            min: origin.minute(),
+        }
+    }
+}
+
+impl Time {
+    pub fn hour(&self) -> u32 {
+        self.hour
+    }
+
+    pub fn minute(&self) -> u32 {
+        self.min
+    }
+}
diff --git a/src/eventlist/eventlist.rs b/src/eventlist/eventlist.rs
index 41462eb..1028dbf 100644
--- a/src/eventlist/eventlist.rs
+++ b/src/eventlist/eventlist.rs
@@ -24,6 +24,7 @@ use serde_derive::Serialize;
 use toml;
 
 use crate::eventlist::event::Event;
+use crate::eventlist::event::EventError;
 
 static FILENAME: &str = "events.toml";
 
@@ -40,6 +41,21 @@ pub struct EventListIterator<'a> {
     list: &'a Vec<Event>,
 }
 
+#[derive(Debug)]
+pub enum EventListError {
+    InvalidDate,
+    TooOld,
+}
+
+impl From<EventError> for EventListError {
+    fn from(error: EventError) -> EventListError {
+        match error {
+            EventError::InvalidDate(_) => EventListError::InvalidDate,
+            EventError::TooOld => EventListError::TooOld,
+        }
+    }
+}
+
 // TODO separate business rule from repository
 impl EventList {
     fn empty() -> Self {
@@ -73,6 +89,32 @@ impl EventList {
             fp.write_all(content.as_bytes()).unwrap();
         }
     }
+
+    /// Load the event list, add an all day event, and save it back.
+    /// Returns the ID of the new event.
+    pub fn add_event_with_date(description: &str, date: &str) -> Result<String, EventListError> {
+        let mut list = EventList::load();
+        let event = Event::new_on_date(description, date)?;
+        let id = String::from(&event.id);
+        list.push(event);
+        list.save();
+        Ok(id)
+    }
+
+    /// Load the event list, add an event with date and time, and save it back.
+    /// Returns the ID of the new event.
+    pub fn add_event_with_date_and_time(
+        description: &str,
+        date: &str,
+        time: &str,
+    ) -> Result<String, EventListError> {
+        let mut list = EventList::load();
+        let event = Event::new_on_date_time(description, date, time).unwrap();
+        let id = String::from(&event.id);
+        list.push(event);
+        list.save();
+        Ok(id)
+    }
 }
 
 impl<'a> IntoIterator for &'a EventList {
diff --git a/src/main.rs b/src/main.rs
index 39e7929..3afdb5e 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -21,7 +21,6 @@ use log;
 mod args;
 mod eventlist;
 
-use crate::eventlist::event::Event;
 use crate::eventlist::eventlist::EventList;
 
 fn main() {
@@ -31,9 +30,14 @@ fn main() {
         log::debug!("Command: {:?}", command);
         match command {
             args::Action::List => list(),
-            args::Action::Add(description, date) => add_with_date(&description, &date),
+            args::Action::Add(description, date) => {
+                let event_id = EventList::add_event_with_date(&description, &date).unwrap();
+                println!("Created new event {}", event_id);
+            }
             args::Action::AddWithTime(description, date, time) => {
-                add_with_date_time(&description, &date, &time)
+                let event_id =
+                    EventList::add_event_with_date_and_time(&description, &date, &time).unwrap();
+                println!("Created new event {}", event_id);
             }
         }
     }
@@ -42,8 +46,10 @@ fn main() {
 fn list() {
     let event_list = EventList::load(); // TODO hide load from outside
     println!("{:^8} | {:^7} | {}", "ID", "ETA", "Description");
+    // TODO: EventList::iter()
     for record in event_list.into_iter() {
         let eta = if let Some(eta) = record.eta() {
+            // TODO: "1d" == Tomorrow; "0d" == Today
             eta
         } else {
             "Over".into()
@@ -52,23 +58,3 @@ fn list() {
         println!("{:>8} | {:>7} | {}", record.id, eta, record.description);
     }
 }
-
-// TODO business rule (should be in EventList)
-fn add_with_date(description: &str, date: &str) {
-    let event = Event::new_on_date(description, date);
-    add_event(event);
-}
-
-fn add_with_date_time(description: &str, date: &str, time: &str) {
-    let event = Event::new_on_date_time(description, date, time);
-    add_event(event);
-}
-
-fn add_event(event: Event) {
-    println!("Adding event {}", event.id);
-
-    let mut event_list = EventList::load();
-    log::debug!("EventList: {:?}", event_list);
-    event_list.push(event);
-    event_list.save();
-}