Timedelta in Python

Python offers powerful tools for working with date and time values. However, one common problem in working with these values is calculating the difference between two dates or times. Python's timedelta module provides an elegant solution to this problem. With the help of timedelta, you can easily perform arithmetic operations on date and time objects. By adding or subtracting a timedelta object to a date or time object, you can get a new date or time object that represents an offset from the original date or time. In this tutorial, we'll dive deeper into the timedelta module in Python and explore some common use cases.

Timedelta in Python

•  timedelta  is a class in Python's datetime module used to represent time duration. 
• It can represent duration in days, hours, minutes, seconds, and microseconds.
• We can import the  timedelta  class by using the construct :  from datetime import timedelta 

Creating a timedelta object

• The  timedelta()   function can be used to create a  timedelta   object.
• There are different ways of creating a timedelta object : 
  • Creating a timedelta object with weeks constructor
  • Creating a timedelta object with days constructor
  • Creating a timedelta object with hours constructor
  • Creating a timedelta object with seconds constructor
  • Creating a timedelta object with microseconds constructor
• Code Sample :

from datetime import timedelta

delta = timedelta(days=10, hours=5, minutes=30, seconds=20)
print("Timedelta:", delta)

# Output
# Timedelta: 10 days, 5:30:20

Creating a timedelta Object with weeks constructor

• We can create a  timedelta   object with weeks constructor using its  weeks  argument.
• Code Sample :

from datetime import timedelta

delta = timedelta(weeks=3)
print("Timedelta:", delta)

# Output
# Timedelta: 21 days, 0:00:00

Creating a timedelta object with days constructor

• We can create a  timedelta   object with days constructor using its  days  argument.
• Code Sample :

from datetime import timedelta

delta = timedelta(days=20)
print("Timedelta:", delta)

# Output
# Timedelta: 20 days, 0:00:00

Creating timedelta object with hours constructor:

• We can create a  timedelta   object with hours constructor using its  hours  argument.
• Code Sample :

from datetime import timedelta

delta = timedelta(hours=122)
print("Timedelta:", delta)

# Output
# Timedelta: 5 days, 2:00:00

Creating a timedelta object with seconds constructor:

• We can create a  timedelta   object with seconds constructor using its  seconds  argument.
• Code Sample :

from datetime import timedelta

delta = timedelta(seconds=3600)
print("Timedelta:", delta)

# Output
# Timedelta: 1:00:00

Creating a timedelta object with microseconds constructor:

• We can create a  timedelta   object with microseconds constructor using its  microseconds  argument.
• Code Sample :

from datetime import timedelta

delta = timedelta(microseconds=500000)
print("Timedelta:", delta)

# Output
# Timedelta: 0:00:00.500000

Timedelta Arithmetic

• The  timedelta  class can be used to perform arithmetic on dates and times. 
• There are many different ways in which we can use the  timedelta  class to perform arithmetic on time duration.
• Here we'll discuss the following ways of manipulating date and time with timedelta : 
  • Find the difference between two dates.
  • Add a time duration to a  datetime  object.
  • Subtract a time duration from a  datetime  object.
  • Add a time duration to a  date  object.
  • Subtract a time duration from a  date  object.
  • Add two   timedelta  objects
  • Subtract two   timedelta  objects
  • Compare two   timedelta  objects

Find the difference between two dates

• To find the difference between two dates we can simply use the subtraction operator.
• The operation will return a   timedelta  object.
• Code Sample :

from datetime import date

d1 = date(2017, 5, 19)
d2 = date(2017, 5, 15)

# Getting the difference between two dates
diff = d1 - d2
print("Time Diff :", diff)
print("Data type of diff : ", type(diff))
print()


# Output
# Time Diff : 4 days, 0:00:00
# Data type of diff :  <class 'datetime.timedelta'>

Add a time duration to a datetime object.

• To add a time duration to a  datetime  object we can use   timedelta  object.
• The resultant is a new  datetime  object.
• Code sample : 

from datetime import datetime
from datetime import timedelta

# Adding a time duration to a datetime object
dt = datetime(2017, 5, 9)
new_date = dt + timedelta(days=7)

print("Orig. date :", dt)
print("New date   :", new_date)
print("Data type of New date :", type(new_date))
print()


# Output
# Orig. date : 2017-05-09 00:00:00
# New date   : 2017-05-16 00:00:00
# Data type of New date : <class 'datetime.datetime'>

Subtract a time duration from a datetime object.

• We can subtract a time duration from a  datetime  object using   timedelta  object.
• The resultant is a new  datetime  object.
• Code sample : 

from datetime import datetime
from datetime import timedelta

# Subtracting a time duration to a datetime object
dt = datetime(2017, 5, 9)
new_date = dt - timedelta(days=7)

print("Orig. date :", dt)
print("New date   :", new_date)
print("Data type of New date :", type(new_date))
print()


# Output
# Orig. date : 2017-05-09 00:00:00
# New date   : 2017-05-02 00:00:00
# Data type of New date : <class 'datetime.datetime'>

Add a time duration to a date object.

• We can add a time duration to a  date  object using   timedelta   object.
• The resultant is a new  date  object.
• Code sample : 

from datetime import date
from datetime import timedelta

# Adding a time duration to a date object
d = date(2017, 5, 19)
new_date = d + timedelta(days=7)

print("Orig. date :", d)
print("New date   :", new_date)
print("Data type of New date :", type(new_date))
print()


# Output
# Orig. date : 2017-05-19
# New date   : 2017-05-26
# Data type of New date : <class 'datetime.date'>

Subtract a time duration from a date object.

• We can subtract a time duration from a  date  object using   timedelta   object.
• The resultant is a new  date  object.
• Code sample : 

from datetime import date
from datetime import timedelta

# Subtracting a time duration to a date object
d = date(2017, 5, 19)
new_date = d - timedelta(days=7)

print("Orig. date :", d)
print("New date   :", new_date)
print("Data type of New date :", type(new_date))
print()

# Output
# Orig. date : 2017-05-19
# New date   : 2017-05-12
# Data type of New date : <class 'datetime.date'>

Add two timedelta objects

• We can add two  timedelta   objects to get a new  timedelta   object.
• Code sample : 

from datetime import timedelta

delta1 = timedelta(days=10)
delta2 = timedelta(hours=12)
result = delta1 + delta2

print("Result:", result)

# Output: 
# Result: 10 days, 12:00:00

Subtract two timedelta objects

• We can subtract two  timedelta   objects to get a new  timedelta   object.
• Code sample : 

from datetime import timedelta

delta1 = timedelta(days=10)
delta2 = timedelta(days=4, hours=10)
result = delta1 - delta2

print("Result:", result)


# Output: 
# Result: 5 days, 14:00:00

Compare two timedelta objects

• We can compare two  timedelta   objects using the usual comparison operators.
• Code sample : 

from datetime import timedelta

delta1 = timedelta(days=10)
delta2 = timedelta(days=9, hours=10)

if delta1 > delta2:
   print("delta1 is greater than delta2")
else:
   print("delta1 is less than or equal to delta2")


# Output
# delta1 is greater than delta2

Timedelta Attributes:

• We can access the number of days, seconds, and microseconds in a  timedelta   object using its attributes
• The name of the attributes are :
  • days, 
  • seconds, and 
  • microseconds respectively.
• Code Sample : 

from datetime import timedelta

delta = timedelta(days=10, hours=5, minutes=30, seconds=20, microseconds=30)

print("Days :", delta.days)
print("Seconds :", delta.seconds)
print("Microseconds :", delta.microseconds)

# Output:
# Days : 10
# Seconds : 19820
# Microseconds : 30

Converting timedelta object to seconds

• We can convert a  timedelta   object to the total number of seconds using its   total_seconds()   method.
• Code Sample : 

from datetime import timedelta

delta = timedelta(hours=1, minutes=30, seconds=20)

seconds = delta.total_seconds()
print("Total seconds:", seconds)

# Output
# Total seconds: 5420.0

Formatting a timedelta object

• We can use the   str()  function and format codes to convert a  timedelta   object to a string.
• Code Sample : 

from datetime import timedelta

delta = timedelta(days=10, hours=5, minutes=30, seconds=20)

delta_string = str(delta)
print("Timedelta string:", delta_string)

# Output
# Timedelta string: 10 days, 5:30:20

How to convert string to timedelta 

• We can convert a string to timedelta using the strptime() function in python.
• The process of converting a string to timedelta is : 
  • First convert the string to  datetime  object using the  strptime()  function.
  • then we calculate the total number of seconds in the obtained datetime object.
  • then we can use the  timedelta()  function of the   datetime   module to get the timedelta value.
• Code Sample : 

import datetime

str_td = "15:12:40"
dt = datetime.datetime.strptime(str_td, "%H:%M:%S")

# Calculating total number of seconds
total_sec = dt.hour*3600 + dt.minute*60 + dt.second
td = datetime.timedelta(seconds=total_sec)

print("Timedelta : ",td)
print("Data Type of td : ", type(td))


# Output
# Timedelta :  15:12:40
# Data Type of td :  <class 'datetime.timedelta'>