The month format specifier doesn't seem to work.
from datetime import datetime
endDate = datetime.strptime('10 3 2011', '%j %m %Y')
print endDate
2011-01-10 00:00:00
endDate = datetime.strptime('21 5 1987', '%j %m %Y')
print endDate
1987-01-21 00:00:00
Now, according to the manual the manual:
%m = Month as a decimal number [01,12].
So, what am I missing, other than the hair I've pulled out trying to understand why my django __filter queries return nothing (the dates going in aren't valid!)? I've tried 03 and 05 to no avail.
Versions of things, platform, architecture et al:
$ python --version
Python 2.7
$ python3 --version
Python 3.1.2
$ uname -r
2.6.35.11-83.fc14.x86_64 (that's Linux/Fedora 14/64-bit).
You can't mix the %j with others format code like %m because if you look in the table that you linked %j is the Day of the year as a decimal number [001,366] so 10 correspondent to the 10 day of the year so it's 01 of January ...
So you have just to write :
>>> datetime.strptime('10 2011', '%j %Y')
datetime.datetime(2011, 1, 10, 0, 0)
Else if you you wanted to use 10 as the day of the mount you should do :
>>> datetime.strptime('10 3 2011', '%d %m %Y')
datetime.datetime(2011, 3, 10, 0, 0)
Isn't %j the "day of year" parser, which may be forcing strptime to choose January 21, overriding the %m rule?
%j specifies a day of the year. It's impossible for the 10th day of the year, January 10, to occur in March, so your month specification is being ignored. Garbage In, Garbage Out.
Related
As we all know, date parsing in Go has it's quirks*.
However, I have now come up against needing to parse a datetime string in CCYY-MM-DDThh:mm:ss[.sss...] to a valid date in Go.
This CCYY format is a format that seems to be ubiquitous in astronomy, essentially the CC is the current century, so although we're in 2022, the century is the 21st century, meaning the date in CCYY format would be 2122.
How do I parse a date string in this format, when we can't specify a coded layout?
Should I just parse in that format, and subtract one "century" e.g., 2106 becomes 2006 in the parsed datetime...?
Has anyone come up against this niche problem before?
*(I for one would never have been able to remember January 2nd, 3:04:05 PM of 2006, UTC-0700 if it wasn't the exact time of my birth! I got lucky)
The time package does not support parsing centuries. You have to handle it yourself.
Also note that a simple subtraction is not enough, as e.g. the 21st century takes place between January 1, 2001 and December 31, 2100 (the year may start with 20 or 21). If the year ends with 00, you do not have to subtract 100 years.
I would write a helper function to parse such dates:
func parse(s string) (t time.Time, err error) {
t, err = time.Parse("2006-01-02T15:04:05[.000]", s)
if err == nil && t.Year()%100 != 0 {
t = t.AddDate(-100, 0, 0)
}
return
}
Testing it:
fmt.Println(parse("2101-12-31T12:13:14[.123]"))
fmt.Println(parse("2122-10-29T12:13:14[.123]"))
fmt.Println(parse("2100-12-31T12:13:14[.123]"))
fmt.Println(parse("2201-12-31T12:13:14[.123]"))
Which outputs (try it on the Go Playground):
2001-12-31 12:13:14.123 +0000 UTC <nil>
2022-10-29 12:13:14.123 +0000 UTC <nil>
2100-12-31 12:13:14.123 +0000 UTC <nil>
2101-12-31 12:13:14.123 +0000 UTC <nil>
As for remembering the layout's time:
January 2, 15:04:05, 2006 (zone: -0700) is a common order in the US, and in this representation parts are in increasing numerical order: January is month 1, 15 hour is 3PM, year 2006 is 6. So the ordinals are 1, 2, 3, 4, 5, 6, 7.
I for one would never have been able to remember January 2nd, 3:04:05 PM of 2006, UTC-0700 if it wasn't the exact time of my birth! I got lucky.
The reason for the Go time package layout is that it is derived from the Unix (and Unix-like) date command format. For example, on Linux,
$ date
Fri Apr 15 08:20:43 AM EDT 2022
$
Now, count from left to right,
Month = 1
Day = 2
Hour = 3 (or 15 = 12 + 3)
Minute = 4
Second = 5
Year = 6
Note: Rob Pike is an author of The Unix Programming Environment
Through Python i'm trying to convert the future date into another format and subtract with current date but it's throwing error.
Python version = Python 3.6.8
from datetime import datetime
enddate = 'Thu Jun 02 08:00:00 EDT 2022'
todays = datetime.today()
print ('Tpday =',todays)
Modified_date1 = datetime.strptime(enddate, ' %a %b %d %H:%M:%S %Z %Y')
subtract_days= Modified_date1 - todays
print (subtract_days.days)
Output
Today = 2022-02-02 08:06:53.687342
Traceback (most recent call last):
File "1.py", line 106, in trusstore_output
Modified_date1 = datetime.strptime(enddate1, ' %a %b %d %H:%M:%S %Z %Y')
File "/usr/lib64/python3.6/_strptime.py", line 565, in _strptime_datetime
tt, fraction = _strptime(data_string, format)
File "/usr/lib64/python3.6/_strptime.py", line 362, in _strptime
(data_string, format))
ValueError: time data ' Thu Jun 02 08:00:00 EDT 2022' does not match format ' %a %b %d %H:%M:%S %Z %Y'
During handling of the above exception, another exception occurred:
Linux server date
$ date
Wed Feb 2 08:08:36 CST 2022
Point 6 in the Documentation tells that not all Timezone formats are available to be parsed by strptime.
%Z [...]
So someone living in Japan may have JST, UTC, and GMT as valid values, but probably not EST. It will raise ValueError for invalid values.
If possible, you could get the server date with the -u flag and parse the UTC timestamp.
date -u
Mi 2. Feb 14:39:11 UTC 2022
PS:
Also watch out for the leading whitespace in your strings.
If EDT is available on your system, the Value Error could be a result of the a mixup between enddate and enddate1.
' Thu Jun 02 08:00:00 EDT 2022' vs. enddate = 'Thu Jun 02 08:00:00 EDT 2022'
Unfortunately, only a subset of timezones is supported by strptime.
If you can ensure that the input does not contain any other timezones than EDT or EST, you could replace these by the corresponding UTC offsets and use %z instead of %Z:
from datetime import datetime
date_str = "Thu Jun 02 08:00:00 EDT 2022"
date_str = date_str.replace("EDT", "-0400")
date_str = date_str.replace("EST", "-0500")
date_parsed = datetime.strptime(date_str, "%a %b %d %H:%M:%S %z %Y")
# 2022-06-02 08:00:00-04:00
print(date_parsed)
As a beginner, creating timestamps or formatted dates ended up being a little more of a challenge than I would have expected. What are some basic examples for reference?
Ultimately you want to review the datetime documentation and become familiar with the formatting variables, but here are some examples to get you started:
import datetime
print('Timestamp: {:%Y-%m-%d %H:%M:%S}'.format(datetime.datetime.now()))
print('Timestamp: {:%Y-%b-%d %H:%M:%S}'.format(datetime.datetime.now()))
print('Date now: %s' % datetime.datetime.now())
print('Date today: %s' % datetime.date.today())
today = datetime.date.today()
print("Today's date is {:%b, %d %Y}".format(today))
schedule = '{:%b, %d %Y}'.format(today) + ' - 6 PM to 10 PM Pacific'
schedule2 = '{:%B, %d %Y}'.format(today) + ' - 1 PM to 6 PM Central'
print('Maintenance: %s' % schedule)
print('Maintenance: %s' % schedule2)
The output:
Timestamp: 2014-10-18 21:31:12
Timestamp: 2014-Oct-18 21:31:12
Date now: 2014-10-18 21:31:12.318340
Date today: 2014-10-18
Today's date is Oct, 18 2014
Maintenance: Oct, 18 2014 - 6 PM to 10 PM Pacific
Maintenance: October, 18 2014 - 1 PM to 6 PM Central
Reference link: https://docs.python.org/3.4/library/datetime.html#strftime-strptime-behavior
>>> import time
>>> print(time.strftime('%a %H:%M:%S'))
Mon 06:23:14
from datetime import datetime
dt = datetime.now() # for date and time
ts = datetime.timestamp(dt) # for timestamp
print("Date and time is:", dt)
print("Timestamp is:", ts)
You might want to check string to datetime operations for formatting.
from datetime import datetime
datetime_str = '09/19/18 13:55:26'
datetime_object = datetime.strptime(datetime_str, '%m/%d/%y %H:%M:%S')
print(type(datetime_object))
print(datetime_object) # printed in default format
Output:
<class 'datetime.datetime'>
2018-09-19 13:55:26
I'm trying to create a DateTime object with a specific UTC timestamp in PowerShell. What's the simplest way to do this?
I tried:
Get-Date
-Format (Get-Culture).DateTimeFormat.UniversalSortableDateTimePattern
-Date "1970-01-01 00:00:00Z"
but I get this output:
1969-12-31 19:00:00Z
It's a few hours off. Where's my lapse in understanding?
The DateTime object itself is being created with the proper UTC time. But when PowerShell prints it out it converts it to my local culture and time zone, thus the difference.
Proof:
$UtcTime = Get-Date -Date "1970-01-01 00:00:00Z"
$UtcTime.ToUniversalTime()
(get-date).ToUniversalTime().ToString("yyyyMMddTHHmmssfffffffZ")
$utctime = New-Object DateTime 1970, 1, 1, 0, 0, 0, ([DateTimeKind]::Utc)
If you print out $utctime, then you get:
1. januar 1970 00:00:00
Also, $utctime.Kind is correctly set to Utc.
$time = [DateTime]::UtcNow | get-date -Format "yyyy-MM-ddTHH:mm:ssZ"
This appears to also work
You can use the SpecifyKind method:
PS C:\IT\s3> $timestamp
Wednesday, July 18, 2018 7:57:14 PM
PS C:\IT\s3> $timestamp.kind
Unspecified
PS C:\IT\s3> $utctimestamp = [DateTime]::SpecifyKind($timestamp,[DateTimeKind]::Utc)
PS C:\IT\s3> $utctimestamp
Wednesday, July 18, 2018 7:57:14 PM
PS C:\IT\s3> $utctimestamp.kind
Utc
This is how it works in .NET, right? PowerShell just calls the ToUniversalTime method. From http://msdn.microsoft.com/en-us/library/system.datetime.touniversaltime.aspx
The Coordinated Universal Time (UTC) is equal to the local time minus the
UTC offset. For more information about the UTC offset, see TimeZone.GetUtcOffset.
The conversion also takes into account the daylight saving time rule that applies
to the time represented by the current DateTime object.
I have a tab delimited file where each record has a timestamp field in 12-hour format:
mm/dd/yyyy hh:mm:ss [AM|PM].
I need to quickly convert these fields to 24-hour time:
mm/dd/yyyy HH:mm:ss.
What would be the best way to do this? I'm running on a Windows platform, but I have access to sed, awk, perl, python, and tcl in addition to the usual Windows tools.
Using Perl and hand-crafted regexes instead of facilities like strptime:
#!/bin/perl -w
while (<>)
{
# for date times that don't use leading zeroes, use this regex instead:
# (?:\d{1,2}/\d{1,2}/\d{4} )(\d{1,2})(?::\d\d:\d\d) (AM|PM)
while (m%(?:\d\d/\d\d/\d{4} )(\d\d)(?::\d\d:\d\d) (AM|PM)%)
{
my $hh = $1;
$hh -= 12 if ($2 eq 'AM' && $hh == 12);
$hh += 12 if ($2 eq 'PM' && $hh != 12);
$hh = sprintf "%02d", $hh;
# for date times that don't use leading zeroes, use this regex instead:
# (\d{1,2}/\d{1,2}/\d{4} )(\d{1,2})(:\d\d:\d\d) (?:AM|PM)
s%(\d\d/\d\d/\d{4} )(\d\d)(:\d\d:\d\d) (?:AM|PM)%$1$hh$3%;
}
print;
}
That's very fussy - but also converts possibly multiple timestamps per line.
Note that the transformation for AM/PM to 24-hour is not trivial.
12:01 AM --> 00:01
12:01 PM --> 12:01
01:30 AM --> 01:30
01:30 PM --> 13:30
Now tested:
perl ampm-24hr.pl <<!
12/24/2005 12:01:00 AM
09/22/1999 12:00:00 PM
12/12/2005 01:15:00 PM
01/01/2009 01:56:45 AM
12/30/2009 10:00:00 PM
12/30/2009 10:00:00 AM
!
12/24/2005 00:01:00
09/22/1999 12:00:00
12/12/2005 13:15:00
01/01/2009 01:56:45
12/30/2009 22:00:00
12/30/2009 10:00:00
Added:
In What is a Simple Way to Convert Between an AM/PM Time and 24 hour Time in JavaScript, an alternative algorithm is provided for the conversion:
$hh = ($1 % 12) + (($2 eq 'AM') ? 0 : 12);
Just one test...probably neater.
It is a 1-line thing in python:
time.strftime('%H:%M:%S', time.strptime(x, '%I:%M %p'))
Example:
>>> time.strftime('%H:%M:%S', time.strptime('08:01 AM', '%I:%M %p'))
'08:01:00'
>>> time.strftime('%H:%M:%S', time.strptime('12:01 AM', '%I:%M %p'))
'00:01:00'
Use Pythons datetime module someway like this:
import datetime
infile = open('input.txt')
outfile = open('output.txt', 'w')
for line in infile.readlines():
d = datetime.strptime(line, "input format string")
outfile.write(d.strftime("output format string")
Untested code with no error checking. Also it reads the entire input file in memory before starting.
(I know there is plenty of room for improvements like with statement...I make this a community wiki entry if anyone likes to add something)
To just convert the hour field, in python:
def to12(hour24):
return (hour24 % 12) if (hour24 % 12) > 0 else 12
def IsPM(hour24):
return hour24 > 11
def to24(hour12, isPm):
return (hour12 % 12) + (12 if isPm else 0)
def IsPmString(pm):
return "PM" if pm else "AM"
def TestTo12():
for x in range(24):
print x, to12(x), IsPmString(IsPM(x))
def TestTo24():
for pm in [False, True]:
print 12, IsPmString(pm), to24(12, pm)
for x in range(1, 12):
print x, IsPmString(pm), to24(x, pm)
This might be too simple thinking, but why not import it into excel, select the entire column and change the date format, then re-export as a tab delimited file? (I didn't test this, but it somehow sounds logical to me :)
Here i have converted 24 Hour system to 12 Hour system.
Try to use this method for your problem.
DateFormat fmt = new SimpleDateFormat("yyyyMMddHHssmm");
try {
Date date =fmt.parse("20090310232344");
System.out.println(date.toString());
fmt = new SimpleDateFormat("dd-MMMM-yyyy hh:mm:ss a ");
String dateInString = fmt.format(date);
System.out.println(dateInString);
} catch (Exception e) {
System.out.println(e.getMessage());
}
RESULT:
Tue Mar 10 23:44:23 IST 2009
10-March-2009 11:44:23 PM
In Python: Converting 12hr time to 24hr time
import re
time1=input().strip().split(':')
m=re.search('(..)(..)',time1[2])
sec=m.group(1)
tz=m.group(2)
if(tz='PM'):
time[0]=int(time1[0])+12
if(time1[0]=24):
time1[0]-=12
time[2]=sec
else:
if(int(time1[0])=12):
time1[0]-=12
time[2]=sec
print(time1[0]+':'+time1[1]+':'+time1[2])
Since you have multiple languages, I'll suggest the following algorithm.
1 Check the timestamp for the existence of the "PM" string.
2a If PM does not exist, simply convert the timestamp to the datetime object and proceed.
2b If PM does exist, convert the timestamp to the datetime object, add 12 hours, and proceed.