diff --git a/sort.go b/sort.go
new file mode 100644
index 0000000..61966c9
--- /dev/null
+++ b/sort.go
@@ -0,0 +1,83 @@
+package timertxt
+
+import (
+	"errors"
+	"sort"
+	"time"
+)
+
+// Flags for defining sort element and order.
+const (
+	SORT_START_DATE_ASC = iota
+	SORT_START_DATE_DESC
+	SORT_FINISH_DATE_ASC
+	SORT_FINISH_DATE_DESC
+)
+
+// Sort allows a TimerList to be sorted by certain predefined fields.
+// See constants SORT_* for fields and sort order.
+func (timerlist *TimerList) Sort(sortFlag int) error {
+	switch sortFlag {
+	case SORT_START_DATE_ASC, SORT_START_DATE_DESC:
+		timerlist.sortByStartDate(sortFlag)
+	case SORT_FINISH_DATE_ASC, SORT_FINISH_DATE_DESC:
+		timerlist.sortByFinishDate(sortFlag)
+	default:
+		return errors.New("Unrecognized sort option")
+	}
+	return nil
+}
+
+type timerlistSort struct {
+	timerlists TimerList
+	by         func(t1, t2 *Timer) bool
+}
+
+func (ts *timerlistSort) Len() int {
+	return len(ts.timerlists)
+}
+
+func (ts *timerlistSort) Swap(l, r int) {
+	ts.timerlists[l], ts.timerlists[r] = ts.timerlists[r], ts.timerlists[l]
+}
+
+func (ts *timerlistSort) Less(l, r int) bool {
+	return ts.by(&ts.timerlists[l], &ts.timerlists[r])
+}
+
+func (timerlist *TimerList) sortBy(by func(t1, t2 *Timer) bool) *TimerList {
+	ts := &timerlistSort{
+		timerlists: *timerlist,
+		by:         by,
+	}
+	sort.Sort(ts)
+	return timerlist
+}
+
+func sortByDate(asc bool, date1, date2 time.Time) bool {
+	if asc { // ASC
+		if !date1.IsZero() && !date2.IsZero() {
+			return date1.Before(date2)
+		}
+		return !date2.IsZero()
+	}
+	// DESC
+	if !date1.IsZero() && !date2.IsZero() {
+		return date1.After(date2)
+	}
+	return date2.IsZero()
+}
+
+func (timerlist *TimerList) sortByStartDate(order int) *TimerList {
+	timerlist.sortBy(func(t1, t2 *Timer) bool {
+		return sortByDate(order == SORT_START_DATE_ASC, t1.StartDate, t2.StartDate)
+	})
+	return timerlist
+}
+
+func (timerlist *TimerList) sortByFinishDate(order int) *TimerList {
+	timerlist.sortBy(func(t1, t2 *Timer) bool {
+		return sortByDate(order == SORT_FINISH_DATE_ASC, t1.FinishDate, t2.FinishDate)
+	})
+	return timerlist
+}
diff --git a/timer.go b/timer.go
new file mode 100644
index 0000000..74c2bbb
--- /dev/null
+++ b/timer.go
@@ -0,0 +1,150 @@
+package timertxt
+
+import (
+	"errors"
+	"fmt"
+	"regexp"
+	"sort"
+	"strings"
+	"time"
+)
+
+var (
+	// DateLayout is used for formatting time.Time into timer.txt date format and vice-versa.
+	DateLayout = time.RFC3339
+
+	addonTagRx = regexp.MustCompile(`(^|\s+)([\w-]+):(\S+)`) // Match additional tags date: '... due:2012-12-12 ...'
+	contextRx  = regexp.MustCompile(`(^|\s+)@(\S+)`)         // Match contexts: '@Context ...' or '... @Context ...'
+	projectRx  = regexp.MustCompile(`(^|\s+)\+(\S+)`)        // Match projects: '+Project...' or '... +Project ...')
+)
+
+type Timer struct {
+	Id             int    // Internal timer id
+	Original       string // Original raw timer text
+	StartDate      time.Time
+	FinishDate     time.Time
+	Finished       bool
+	Notes          string // Notes part of timer text
+	Projects       []string
+	Contexts       []string
+	AdditionalTags map[string]string // Addon tags will be available here
+}
+
+// String returns a complete timer string in timer.txt format.
+//
+// Contexts, Projects, and additional tags are alphabetically sorted,
+// and appended at the end in the following order:
+// Contexts, Projects, Tags
+//
+// For example:
+// "2019-02-15T11:43:00-0600 Working on Go Library @home @personal +timertxt customTag1:Important! due:Today"
+// "x 2019-02-15T10:00:00-0600 2019-02-15T06:00:00-0600 Creating Go Library Repo @home @personal +timertxt customTag1:Important! due:Today"
+func (timer Timer) String() string {
+	var text string
+	if timer.Finished {
+		text += "x "
+		if timer.HasFinishDate() {
+			text += fmt.Sprintf("%s ", timer.FinishDate.Format(DateLayout))
+		}
+	}
+	text += fmt.Sprintf("%s ", timer.StartDate.Format(DateLayout))
+	text += timer.Notes
+	if len(timer.Contexts) > 0 {
+		sort.Strings(timer.Contexts)
+		for _, context := range timer.Contexts {
+			text += fmt.Sprintf(" @%s", context)
+		}
+	}
+	if len(timer.Projects) > 0 {
+		sort.Strings(timer.Projects)
+		for _, project := range timer.Projects {
+			text += fmt.Sprintf(" +%s", project)
+		}
+	}
+	if len(timer.AdditionalTags) > 0 {
+		// Sort map alphabetically by keys
+		keys := make([]string, 0, len(timer.AdditionalTags))
+		for key := range timer.AdditionalTags {
+			keys = append(keys, key)
+		}
+		sort.Strings(keys)
+		for _, key := range keys {
+			text += fmt.Sprintf(" %s:%s", key, timer.AdditionalTags[key])
+		}
+	}
+	return text
+}
+
+// NewTimer creates a new empty Timer with default values. (StartDate is set to Now())
+func NewTimer() Timer {
+	timer := Timer{}
+	timer.StartDate = time.Now()
+	return timer
+}
+
+// ParseTimer parses the input text string into a Timer struct
+func ParseTimer(text string) (*Timer, error) {
+	var err error
+	timer := Timer{}
+	timer.Original = strings.Trim(text, "\t\n\r ")
+	originalParts := strings.Fields(timer.Original)
+
+	// Check for finished
+	if originalParts[0] == "x" {
+		timer.Finished = true
+		// If it's finished, there _must_ be a finished date
+		if timer.FinishDate, err = time.Parse(DateLayout, originalParts[1]); err != nil {
+			return nil, errors.New("Timer marked finished, but failed to parse FinishDate: " + err.Error())
+		}
+		originalParts = originalParts[2:]
+	}
+	if timer.StartDate, err = time.Parse(DateLayout, originalParts[0]); err != nil {
+		return nil, errors.New("Unable to parse StartDate: " + err.Error())
+	}
+	originalParts = originalParts[1:]
+	var notes []string
+	for _, v := range originalParts {
+		if strings.HasPrefix("@", v) {
+			// Contexts
+			timer.Contexts = append(timer.Contexts, v)
+		} else if strings.HasPrefix("+", v) {
+			// Projects
+			timer.Projects = append(timer.Projects, v)
+		} else if strings.Contains(":", v) {
+			// Additional tags
+			tagPts := strings.Split(v, ":")
+			if tagPts[0] != "" && tagPts[1] != "" {
+				timer.AdditionalTags[tagPts[0]] = tagPts[1]
+			}
+		} else {
+			notes = append(notes, v)
+		}
+	}
+	timer.Notes = strings.Join(notes, " ")
+
+	return timer, nil
+}
+
+// Timer returns a complete timer string in timer.txt format.
+// See *Timer.String() for further information
+func (timer *Timer) Timer() string {
+	return timer.String()
+}
+
+// Finish sets Timer.Finished to true if the timer hasn't already been finished.
+// Also sets Timer.FinishDate to time.Now()
+func (timer *Timer) Finish() bool {
+	if !timer.Finished {
+		timer.Finished = true
+		timer.FinishDate = time.Now()
+	}
+}
+
+// Reopen sets Timer.Finished to 'false' if the timer was finished
+// Also resets Timer.FinishDate
+func (timer *Timer) Reopen() {
+	if timer.Finished {
+		timer.Finished = false
+		timer.FinishDate = time.Date(1, 1, 1, 0, 0, 0, 0, time.UTC) // time.IsZero() value
+	}
+}
diff --git a/timerlist.go b/timerlist.go
new file mode 100644
index 0000000..fd5117e
--- /dev/null
+++ b/timerlist.go
@@ -0,0 +1,170 @@
+package timertxt
+
+import (
+	"bufio"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"strings"
+)
+
+// TimerList represents a list of timer.txt timer entries.
+// It is usually loasded from a whole timer.txt file.
+type TimerList []Timer
+
+// NewTimerList creates a new empty TimerList.
+func NewTimerList() TimerList {
+	timerlist := TimerList{}
+	return timerlist
+}
+
+// String returns a complete list of timers in timer.txt format.
+func (timerlist TimerList) String() string {
+	var ret string
+	for _, timer := range timerlist {
+		ret += fmt.Sprintf("%s\n", timer.String())
+	}
+	return ret
+}
+
+// AddTimer appends a Timer to the current TimerList and takes care to set the Timer.Id correctly
+func (timerlist *TimerList) AddTimer(timer *Timer) {
+	timer.Id = 0
+	for _, t := range *timerlist {
+		if t.Id > timer.Id {
+			timer.Id = t.Id
+		}
+	}
+	timer.Id += 1
+	*timerlist = append(*timerlist, *timer)
+}
+
+// GetTimer returns the Timer with the given timer 'id' from the TimerList.
+// Returns an error if Timer could not be found.
+func (timerlist *TimerList) GetTimer(id int) (*Timer, error) {
+	for i := range *timerlist {
+		if ([]Timer(*timerlist))[i].Id == id {
+			return &([]Timer(*timerlist))[i], nil
+		}
+	}
+	return nil, errors.new("timer not found")
+}
+
+// RemoveTimerById removes any Timer with given Timer 'id' from the TimerList.
+// Returns an error if no Timer was removed.
+func (timerlist *TimerList) RemoveTimerById(id int) error {
+	var newList TimerList
+	found := false
+	for _, t := range *timerlist {
+		if t.Id != id {
+			newList = append(newList, t)
+		} else {
+			found = true
+		}
+	}
+	if !found {
+		return errors.new("timer not found")
+	}
+	*timerlist = newList
+	return nil
+}
+
+// RemoveTimer removes any Timer from the TimerList with the same String representation as the given Timer.
+// Returns an error if no Timer was removed.
+func (timerlist *TimerList) RemoveTimer(timer Timer) error {
+	var newList TimerList
+	found := false
+	for _, t := range *timerlist {
+		if t.String() != timer.String() {
+			newList = append(newList, t)
+		} else {
+			found = true
+		}
+	}
+	if !found {
+		return errors.New("timer not found")
+	}
+	*timerlist = newList
+	return nil
+}
+
+// Filter filters the current TimerList for the given predicate (a function that takes a timer as input and returns a
+// bool), and returns a new TimerList. The original TimerList is not modified.
+func (timerlist *TimerList) Filter(predicate func(Timer) bool) *TimerList {
+	var newList TimerList
+	for _, t := range *timerlist {
+		if predicate(t) {
+			newList = append(newList, t)
+		}
+	}
+	return &newList
+}
+
+// LoadFromFile loads a TimerList from *os.File.
+// Note: This will clear the current TimerList and overwrite it's contents with whatever is in *os.File.
+func (timerlist *TimerList) LoadFromFile(file *os.File) error {
+	*timerlist = []Timer{} // Empty timerlist
+	timerId := 1
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		text := strings.Trim(scanner.Text(), "\t\n\r") // Read Line
+		// Ignore blank lines
+		if text == "" {
+			continue
+		}
+		timer, err := ParseTimer(text)
+		if err != nil {
+			return err
+		}
+		timer.Id = timerId
+		*timerlist = append(*timerlist, *timer)
+		timerId++
+	}
+	if err := scanner.Err(); err != nil {
+		return err
+	}
+	return nil
+}
+
+// WriteToFile writes a TimerList to *os.File.
+func (timerlist *TimerList) LoadFromFilename(filename string) error {
+	file, err := os.Open(filename)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+	return timerlist.LoadFromFile(file)
+}
+
+// WriteToFilename writes a TimerList to the specified file (most likely called "timer.txt").
+func (timerlist *TimerList) WriteToFilename(filename string) error {
+	return ioutil.WriteFile(filename, []byte(timerlist.String()), 0640)
+}
+
+// LoadFromFile loads and returns a TimerList from *os.File.
+func LoadFromFile(file *os.File) (TimerList, error) {
+	timerlist := TimerList{}
+	if err := timerlist.LoadFromFile(file); err != nil {
+		return nil, err
+	}
+	return timerlist, nil
+}
+
+// WriteToFile writes a TimerList to *os.File.
+func WriteToFile(timerlist *TimerList, file *os.File) error {
+	return timerlist.WriteToFile(file)
+}
+
+// LoadFromFilename loads and returns a TimerList from a file (most likely called "timer.txt")
+func LoadFromFilename(filename string) (TimerList, error) {
+	timerlist := TimerList{}
+	if err := timerlist.LoadFromFilename(filename); err != nil {
+		return nil, err
+	}
+	return timerlist, nil
+}
+
+// WriteToFilename write a TimerList to the specified file (most likely called "timer.txt")
+func WriteToFilename(timerlist *TimerList, filename string) error {
+	return timerlist.WriteToFilename(filename)
+}