What was midnight yesterday as an epoch time?

Question

I\'m trying to get my head around the datetime module. I know the time now as an epoch and the time an event last happened (as an epoch time). What I need to do is figure

Answer 1

import time

start_str = time.strftime( "%m/%d/%Y" ) + " 00:00:00"
end_str = time.strftime( "%m/%d/%Y ") + " 23:59:59"
start_ts = int( time.mktime( time.strptime( start_str, "%m/%d/%Y %H:%M:%S" ) ) )
end_ts = int( time.mktime( time.strptime( end_str, "%m/%d/%Y %H:%M:%S" ) ) )

print (start_ts) # timestamp today at 00:00:00
print (end_ts) # timestamp today at 23:59:59
# 1552435200
# 1552521599

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Source Python get unix epoch for today’s midnight and today’s 23:59:59 (start of day, end of day)

Answer 2

Given such a timestamp, you can use divmod to compute the number of days since the epoch (which you don't care about), and how many seconds are leftover (which you do):

days_since, remaining_seconds = divmod(t, 24*3600)  # Divide by number of seconds in one day

Then, you subtract the leftover seconds from your original timestamp, which produces midnight of the current day.

t -= remaining_seconds

Rounding up is as simple as shifting your target timestamp forward exactly one day before rounding down.

tomorrow_t = t + 24 * 3600
days_since, remaining_seconds = divmod(tomorrow_t, 24*3600)
t = tomorrow_t - remaining_seconds

Answer 3

In the Middle of the Night

Generating the last midnight is easy:

from datetime import datetime, time

midnight = datetime.combine(datetime.today(), time.min)

That combines today's date (you can use date() or a datetime() instance, your pick), together with time.min to form a datetime object at midnight.

Yesterday

With a timedelta() you can calculate the previous midnight:

from datetime import timedelta

yesterday_midnight = midnight - timedelta(days=1)

That Was Yesterday

Now test if your timestamp is in between these two points:

timestamp = datetime.fromtimestamp(some_timestamp_from_your_log)
if yesterday_midnight <= timestamp < midnight:
    # this happened between 00:00:00 and 23:59:59 yesterday

All Together Now

Combined into one function:

from datetime import datetime, time, timedelta

def is_yesterday(timestamp):
    midnight = datetime.combine(datetime.today(), time.min)
    yesterday_midnight = midnight - timedelta(days=1)
    return yesterday_midnight <= timestamp < midnight:

if is_yesterday(datetime.fromtimestamp(some_timestamp_from_your_log)):
    # ...

Answer 4

To get the specific timezone's midnight timestamp:

from datetime import datetime
import pytz

TZ = "Asia/Shanghai"
datetime.now(pytz.timezone(TZ)).replace(hour=0, minute=0, second=0, microsecond=0).timestamp()

Answer 5

You can use this code:

import time

seconds_of_day = 24 * 60 * 60  # 86400
last_midnight = (round(time.time()) // seconds_of_day) * seconds_of_day
yesterday_last_midnight = last_midnight - seconds_of_day

Answer 6

Midnight at the start of today is:

midnight = (int(time.time() // 86400)) * 86400

so yesterday's midnight is:

midnight = (int(time.time() // 86400)) * 86400 - 86400