Returns the time passed since an unix timestamp as a formatted string.

time-since.py

import time, math

# Sample timestamp to test.
dTs = 1610033721

def returnTimeSince(unixtimestamp: int) -> str:
	# String which will contain formatted time.
	timesince = ""
	# Get the difference between the argument timestamp and current timestamp.
	# Note: time.time() returns a float.
	diffTs = round(time.time()) - unixtimestamp

	if (diffTs / 31536000) >= 1:
		# Value can be expressed in years.
		years = math.floor(diffTs / 31536000)

		timesince = "{0} {1}".format(years, "year" if years == 1 else "years")
	elif ((diffTs * 100) / 262800288) >= 1:
		# Value can be displayed in months.
		months = math.floor((diffTs * 100) / 262800288)

		timesince = "{0} {1}".format(months, "month" if months == 1 else "months")
	elif (diffTs / 604800) >= 1:
		# Value can be displayed in weeks.
		weeks = math.floor(diffTs / 604800)

		timesince = "{0} {1}".format(weeks, "week" if weeks == 1 else "weeks")
	elif (diffTs / 86400) >= 1:
		# Value can be displayed in days.
		days = math.floor(diffTs / 86400)

		timesince = "{0} {1}".format(days, "day" if days == 1 else "days")
	elif (diffTs / 3600) >= 1:
		# Value can be displayed in hours.
		hours = math.floor(diffTs / 3600)

		timesince = "{0} {1}".format(hours, "hour" if hours == 1 else "hours")
	elif (diffTs / 60) >= 1:
		# Value can be displayed in minutes.
		minutes = math.floor(diffTs / 60)

		timesince = "{0} {1}".format(minutes, "minute" if minutes == 1 else "minutes")
	else:
		# Value can be displayed in seconds only.
		timesince = "{0} {1}".format(diffTs, "second" if diffTs == 1 else "seconds")

	# To indicate that it is the end of formatted string.
	timesince += " ago."
	return timesince

print("Time passed since test: {0}".format(returnTimeSince(dTs)))