time between now and the next 2:30 am?
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From: Jim on 23 Jul 2010 19:36 Thank you again to everyone; I greatly appreciate the help. I ended with essentially what Christian advised and it seems to work fine. FWIW, below is the rouine (I couldn't figure out how to do it without the kludgy x variable). The background is that this is a Django context processor that makes available the time until the next 2:30 because that is when the web site is rebuilt. I hope the code isn't too much mangled by the online editor, Jim .............................................................................. import time, datetime from django.conf import settings WARNING_MINS=10 # How many mins before update time should start warning? WARNING_SECS=60*WARNING_MINS def current_time_processor(req): """Add current time information to the Context """ # Calculate time until the next 2:30 am x=datetime.datetime(2010,7,23) # actual date doesn't matter? dt_localtime=x.fromtimestamp(time.time()) dt_twothirty=dt_localtime.replace(hour=settings.UPDATE_TIME_HOURS,minute=settings.UPDATE_TIME_MINS,second=0,microsecond=0) dd_diff=dt_twothirty-dt_localtime secs_until_twothirty=dd_diff.seconds if secs_until_twothirty<WARNING_SECS: w='This site shuts down every night at %02d:%02d local time, to refresh the database. There are fewer than %d minutes until that shutdown. If you have not completed your work when the site shuts down then you will lose your work.' % (settings.UPDATE_TIME_HOURS,settings.UPDATE_TIME_MINS,WARNING_MINS,) else: w=None return {'CURRENT_LOCAL_TIME': time.asctime(time.localtime()), 'TIME_WARNING':w}
From: MRAB on 23 Jul 2010 20:52 Jim wrote: > Thank you again to everyone; I greatly appreciate the help. I ended > with essentially what Christian advised and it seems to work fine. > FWIW, below is the rouine (I couldn't figure out how to do it without > the kludgy x variable). The background is that this is a Django > context processor that makes available the time until the next 2:30 > because that is when the web site is rebuilt. > > I hope the code isn't too much mangled by the online editor, > Jim > > ............................................................................. > > import time, datetime > from django.conf import settings > > WARNING_MINS=10 # How many mins before update time should start > warning? > WARNING_SECS=60*WARNING_MINS > > def current_time_processor(req): > """Add current time information to the Context > """ > # Calculate time until the next 2:30 am > x=datetime.datetime(2010,7,23) # actual date doesn't matter? > dt_localtime=x.fromtimestamp(time.time()) > Why not: dt_localtime = datetime.datetime.now() > dt_twothirty=dt_localtime.replace(hour=settings.UPDATE_TIME_HOURS,minute=settings.UPDATE_TIME_MINS,second=0,microsecond=0) You're changing the time of day, but not the date. You might want to add a day to the shutdown time if it's earlier than the current time. > dd_diff=dt_twothirty-dt_localtime > secs_until_twothirty=dd_diff.seconds > if secs_until_twothirty<WARNING_SECS: > w='This site shuts down every night at %02d:%02d local time, > to refresh the database. There are fewer than %d minutes until that > shutdown. If you have not completed your work when the site shuts > down then you will lose your work.' % > (settings.UPDATE_TIME_HOURS,settings.UPDATE_TIME_MINS,WARNING_MINS,) > else: > w=None > return {'CURRENT_LOCAL_TIME': time.asctime(time.localtime()), > 'TIME_WARNING':w}
From: John Nagle on 24 Jul 2010 03:11 On 7/23/2010 10:01 AM, Jim wrote: > How can I calculate how much time is between now and the next 2:30 > am? Naturally I want the system to worry about leap years, etc. > > Thanks, > Jim DAYSECS = 24*60*60 GOALSECS = (2*60 + 30)*60 now = (GOALSECS + DAYSECS - (int(time.time()) % DAYSECS)) % DAYSECS This is for UT; the adjustment for timezone should be obvious. John Nagle
From: Jim on 24 Jul 2010 07:21
On Jul 23, 8:52 pm, MRAB <pyt...(a)mrabarnett.plus.com> wrote: > > dt_twothirty=dt_localtime.replace(hour=settings.UPDATE_TIME_HOURS,minute=se ttings.UPDATE_TIME_MINS,second=0,microsecond=0) > > You're changing the time of day, but not the date. You might want to add > a day to the shutdown time if it's earlier than the current time. I started out by finding the right date (I used a less-than test and toordinal and fromordinal() ). However, after some trials, I came to believe that I don't need to find the right date. The part of that calculation I need, and later refer to, is the .seconds attribute. I perceive that the way TimeDelta objects are laid out, the seconds attribute will be the same, regardless of whether I calculate it using 2:30 today or first finding which is the right date and using its 2:30. That is, as I understood it, if it is now 2:29 then the .seconds attribute will be 60. If it is now 2:31 then the .seconds attribute will be 24*60*60-60. I believe this holds regardless of which day I use. >>> import time,datetime >>> x=datetime.datetime(2010,7,23) >>> dt_localtime=x.fromtimestamp(time.time()) >>> dt_localtime datetime.datetime(2010, 7, 24, 7, 17, 46, 122642) >>> dt_twothirty=dt_localtime.replace(hour=2,minute=30,second=0,microsecond=0) >>> print dt_twothirty 2010-07-24 02:30:00 >>> dd_diff=dt_twothirty-dt_localtime >>> print dd_diff -1 day, 19:12:13.877358 >>> dt_tomorrow_twothirty=dt_localtime.replace(day=25,hour=2,minute=30,second=0,microsecond=0) >>> print dt_tomorrow_twothirty 2010-07-25 02:30:00 >>> dd_tomorrow_diff=dt_tomorrow_twothirty-dt_localtime >>> print dd_tomorrow_diff 19:12:13.877358 Tested it, of course. Not that I haven't gotten things wrong in the past, even though I tested them. :-} Jim |