Overview

It provides various time-related functions to work with time.

DST - Daylight Saving Time

import time
import datetime

Commonly used functions of module:

• time.time() - It returns time in seconds since epoch as float. On Windows and most unix systems epoch is 1 Jan - 1970 00:00:00 (UTC) and leap seconds are not counted. Output of this function can be passed to other functions like gmtime(),localtime(), datetime.datetime.fromtimestamp() to convert it to proper structured format.

print(time.gmtime(time.time()))
print(time.localtime(time.time()))
print(datetime.datetime.fromtimestamp(time.time()))

time.struct_time(tm_year=2019, tm_mon=2, tm_mday=19, tm_hour=13, tm_min=56, tm_sec=5, tm_wday=1, tm_yday=50, tm_isdst=0)
time.struct_time(tm_year=2019, tm_mon=2, tm_mday=19, tm_hour=13, tm_min=56, tm_sec=5, tm_wday=1, tm_yday=50, tm_isdst=0)
2019-02-19 13:56:05.123462

• time.gmtime([secs]) - It turns seconds provided to struct_time object in UTC since epoch. struct_time has same interface as namedtuple. If secs not provided then current time provided by time() will be used. Fraction part of seconds provided as float is ignored.
• time.localtime([secs]) - It returns struct_time object as local time.

print(time.gmtime(60))
print(time.gmtime(3600))
curr_time = time.gmtime()
print(curr_time.tm_zone)
print(curr_time)
curr_time = time.localtime()
print(curr_time.tm_zone)
print(curr_time)

time.struct_time(tm_year=1970, tm_mon=1, tm_mday=1, tm_hour=0, tm_min=1, tm_sec=0, tm_wday=3, tm_yday=1, tm_isdst=0)
time.struct_time(tm_year=1970, tm_mon=1, tm_mday=1, tm_hour=1, tm_min=0, tm_sec=0, tm_wday=3, tm_yday=1, tm_isdst=0)
GMT
time.struct_time(tm_year=2019, tm_mon=2, tm_mday=19, tm_hour=13, tm_min=56, tm_sec=5, tm_wday=1, tm_yday=50, tm_isdst=0)
UTC
time.struct_time(tm_year=2019, tm_mon=2, tm_mday=19, tm_hour=13, tm_min=56, tm_sec=5, tm_wday=1, tm_yday=50, tm_isdst=0)

• time.ctime([secs]) - Converts time provided in seconds to string representing local time.
• time.asctime([t]) - It accepts tuple of 9 fields or struct_time object to format Mon Jan 01 00:00:00 1970.If t is not provided then current system time is used.

print(time.ctime(60))
print(time.ctime(3600))
print(time.ctime())
print(time.asctime(time.localtime()))
print(time.asctime(time.gmtime()))
print(time.asctime((1992,1,1,5,30,0,3,1,0)))

Thu Jan  1 00:01:00 1970
Thu Jan  1 01:00:00 1970
Tue Feb 19 13:56:05 2019
Tue Feb 19 13:56:05 2019
Tue Feb 19 13:56:05 2019
Thu Jan  1 05:30:00 1992

• time.strftime(format[,t]) - Converts time represented as tuple or struct_time object to string provided as format. It t is not provided then current time returned by localtime() is used.
• time.strptime(string[,format]) - Parse a time represented as string according to format and returns struct_tuple object. Default formating if not provided is %a %b %d %H:%M:%S %Y which is same one printed by ctime().

Refer to this link for formatting options.

print(time.strftime('%Y-%m-%d %H:%M:%S'))
print(time.strftime('%Y-%m-%d %H:%M:%S', time.gmtime(60)))
print(time.strftime('%Y-%m-%d %H:%M:%S', time.gmtime(3600)))
print(time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(60)))
print(time.strptime('Jan 1 - 2012 10:10:10',"%b %d - %Y %H:%M:%S"))
print(time.strptime('Mon Jan  1 00:01:00 2018'))

2019-02-19 13:56:05
1970-01-01 00:01:00
1970-01-01 01:00:00
1970-01-01 00:01:00
time.struct_time(tm_year=2012, tm_mon=1, tm_mday=1, tm_hour=10, tm_min=10, tm_sec=10, tm_wday=6, tm_yday=1, tm_isdst=-1)
time.struct_time(tm_year=2018, tm_mon=1, tm_mday=1, tm_hour=0, tm_min=1, tm_sec=0, tm_wday=0, tm_yday=1, tm_isdst=-1)

• time.sleep(secs) - Suspends execution of the thread in which it executed by a number of seconds. After waking up from sleep after that many second a thread might not get immediate execution as it'll be handled by the scheduler and will go to the ready state. Based on the priority scheduler will execute it.
• time.struct_time - It's an object with the same interface as that of namedtuple. Method mentioned above like strptime(), gmtime() and localtime() returns time represented as this object.

%%time
## Note below that it takes more time to execute cell due to waiting of seconds. Actual execution time is quite less.
def waiting(title, secs):
    time.sleep(secs)
    print('Waiting : '+str(secs)+ ' before printing title : '+title)

waiting('Hello World', 3)

Waiting : 3 before printing title : Hello World
CPU times: user 0 ns, sys: 4 ms, total: 4 ms
Wall time: 3 s

curr_time = time.gmtime()
print(type(curr_time))
print(curr_time)
#tm_mon[1-12], tm_mday[1-31],tm_hour[0-23],tm_min[0-59],tm_sec[0-61],tm_wday[0-6]0 is Sunday,tm_yday[1-366],
# tm_idst[-1,0,1] - 1 Daylight Saving time,0 Not DST, -1 - Will results in set by system.
curr_time.tm_year, curr_time.tm_mon, curr_time.tm_mday, curr_time.tm_hour,curr_time.tm_min, curr_time.tm_sec, curr_time.tm_wday, curr_time.tm_yday, curr_time.tm_isdst

<class 'time.struct_time'>
time.struct_time(tm_year=2019, tm_mon=2, tm_mday=19, tm_hour=13, tm_min=56, tm_sec=8, tm_wday=1, tm_yday=50, tm_isdst=0)

(2019, 2, 19, 13, 56, 8, 1, 50, 0)