Python Program to Find Difference between Current Time and Given Time

Given two times h1:m1 and h2:m2 in 24-hour clock format, where the current time is h1:m1, the task is to calculate the difference between these two times in minutes and display it in h:m format. For Example:

Input: h1 = 7, m1 = 20, h2 = 9, m2 = 45
Output: 2: 25
Explanation: difference between 7:20 and 9:45 is 145 minutes, which equals 2 hours and 25 minutes.

Let's explore different methods to find difference between current time and given time.

Using datetime Module

This method uses Python’s built-in datetime module to easily calculate the time difference by converting both times into datetime objects.

from datetime import datetime, timedelta

h1, m1, h2, m2 = 7, 20, 9, 45

t1 = datetime.strptime("{}:{}".format(h1, m1), "%H:%M")
t2 = datetime.strptime("{}:{}".format(h2, m2), "%H:%M")

if t2 < t1:
    t2 += timedelta(days=1)

diff = t2 - t1
h, m = divmod(diff.seconds // 60, 60)
print("{} : {}".format(h, m))

2 : 25

Explanation:

• datetime.strptime(...): Converts given times into datetime objects.
• if t2 < t1: Adjusts for next day if the given time is earlier.
• divmod(diff.seconds // 60, 60): Converts total minutes into hours and minutes.
• "{}".format(...): Inserts variable values into the string in the correct order for clean output.

Using timedelta

This method uses Python’s timedelta class to represent both times as durations and directly find the difference between them.

from datetime import timedelta

h1, m1, h2, m2 = 7, 20, 9, 45

t1 = timedelta(hours=h1, minutes=m1)
t2 = timedelta(hours=h2, minutes=m2)

if t2 < t1:
    t2 += timedelta(days=1)

diff = t2 - t1
h, m = divmod(diff.seconds // 60, 60)
print("{} : {}".format(h, m))

2 : 25

Explanation:

• timedelta(hours, minutes): Stores both times as total durations.
• if t2 < t1: Adds a day for next-day difference.
• divmod(...): Splits minutes into hours and remaining minutes.

Using time Module

This method converts both times into total seconds using the time module and then calculates their difference in hours and minutes.

import time

h1, m1, h2, m2 = 7, 20, 9, 45

t1 = time.mktime((2025, 11, 12, h1, m1, 0, 0, 0, 0))
t2 = time.mktime((2025, 11, 12, h2, m2, 0, 0, 0, 0))

if t2 < t1:
    t2 += 86400

diff = t2 - t1
h, m = divmod(int(diff // 60), 60)
print("{} : {}".format(h, m))

2 : 25

Explanation:

• time.mktime(...): Converts given times to total seconds.
• if t2 < t1: Adds 24 hours if the given time is next day.
• h, m = divmod(int(diff // 60), 60): Convert seconds into total minutes, then split into hours and minutes.

Using Mathematical Calculation

This method manually converts hours and minutes into total minutes and computes the difference using simple arithmetic operations

h1, m1, h2, m2 = 7, 20, 9, 45

t1 = h1 * 60 + m1
t2 = h2 * 60 + m2

if t1 == t2:
    print("Both are same times")
else:
    diff = t2 - t1 if t2 > t1 else (24 * 60 - (t1 - t2))
    h = diff // 60
    m = diff % 60
    print("{} : {}".format(h, m))

2 : 25

Explanation:

• h1 * 60 + m1: Converts both times into total minutes.
• if t1 == t2: Checks if both times are the same.
• diff = t2 - t1 if t2 > t1 else (24 * 60 - (t1 - t2)): Calculate the time difference; adjust if it crosses midnight.
• h = diff // 60, m = diff % 60: Convert total minutes into hours and remaining minutes.

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