obspy.core.utcdatetime.UTCDateTime

class UTCDateTime(*args, **kwargs)[source]

Bases: builtins.object

A UTC-based datetime object.

This datetime class is based on the POSIX time, a system for describing instants in time, defined as the number of seconds elapsed since midnight Coordinated Universal Time (UTC) of Thursday, January 1, 1970. Using a single float timestamp allows higher precision as the default Python datetime.datetime class. It features the full ISO8601:2004 specification and some additional string patterns during object initialization.

Parameters:
  • args (int, float, str, datetime.datetime, optional) The creation of a new UTCDateTime object depends from the given input parameters. All possible options are summarized in the Examples section below.
  • iso8601 (bool, optional) Enforce ISO8601:2004 detection. Works only with a string as first input argument.
  • precision (int, optional) Sets the precision used by the rich comparison operators. Defaults to 6 digits after the decimal point. See also Precision section below.

Changed in version 0.5.1: UTCDateTime is no longer based on Python’s datetime.datetime class instead uses timestamp as a single floating point value which allows higher precision.

Supported Operations

UTCDateTime = UTCDateTime + delta
Adds/removes delta seconds (given as int or float) to/from the current UTCDateTime object and returns a new UTCDateTime object. See also: __add__().
delta = UTCDateTime - UTCDateTime
Calculates the time difference in seconds between two UTCDateTime objects. The time difference is given as float data type and may also contain a negative number. See also: __sub__().

Examples

  1. Using a timestamp.

    >>> UTCDateTime(0)
    UTCDateTime(1970, 1, 1, 0, 0)
    
    >>> UTCDateTime(1240561632)
    UTCDateTime(2009, 4, 24, 8, 27, 12)
    
    >>> UTCDateTime(1240561632.5)
    UTCDateTime(2009, 4, 24, 8, 27, 12, 500000)
    
  2. Using a ISO8601:2004 string. The detection may be enforced by setting the iso8601 parameter to True.

    • Calendar date representation.

      >>> UTCDateTime("2009-12-31T12:23:34.5")
      UTCDateTime(2009, 12, 31, 12, 23, 34, 500000)
      
      >>> UTCDateTime("20091231T122334.5")           # compact
      UTCDateTime(2009, 12, 31, 12, 23, 34, 500000)
      
      >>> UTCDateTime("2009-12-31T12:23:34.5Z")      # w/o time zone
      UTCDateTime(2009, 12, 31, 12, 23, 34, 500000)
      
      >>> UTCDateTime("2009-12-31T12:23:34+01:15")   # w/ time zone
      UTCDateTime(2009, 12, 31, 11, 8, 34)
      
    • Ordinal date representation.

      >>> UTCDateTime("2009-365T12:23:34.5")
      UTCDateTime(2009, 12, 31, 12, 23, 34, 500000)
      
      >>> UTCDateTime("2009365T122334.5")            # compact
      UTCDateTime(2009, 12, 31, 12, 23, 34, 500000)
      
      >>> UTCDateTime("2009001", iso8601=True)       # enforce ISO8601
      UTCDateTime(2009, 1, 1, 0, 0)
      
    • Week date representation.

      >>> UTCDateTime("2009-W53-7T12:23:34.5")
      UTCDateTime(2010, 1, 3, 12, 23, 34, 500000)
      
      >>> UTCDateTime("2009W537T122334.5")           # compact
      UTCDateTime(2010, 1, 3, 12, 23, 34, 500000)
      
      >>> UTCDateTime("2009W011", iso8601=True)      # enforce ISO8601
      UTCDateTime(2008, 12, 29, 0, 0)
      
  3. Using not ISO8601 compatible strings.

    >>> UTCDateTime("1970-01-01 12:23:34")
    UTCDateTime(1970, 1, 1, 12, 23, 34)
    
    >>> UTCDateTime("1970,01,01,12:23:34")
    UTCDateTime(1970, 1, 1, 12, 23, 34)
    
    >>> UTCDateTime("1970,001,12:23:34")
    UTCDateTime(1970, 1, 1, 12, 23, 34)
    
    >>> UTCDateTime("20090701121212")
    UTCDateTime(2009, 7, 1, 12, 12, 12)
    
    >>> UTCDateTime("19700101")
    UTCDateTime(1970, 1, 1, 0, 0)
    
    >>> UTCDateTime("20110818_03:00:00")
    UTCDateTime(2011, 8, 18, 3, 0)
    
  4. Using multiple arguments in the following order: year, month, day[, hour[, minute[, second[, microsecond]]]. The year, month and day arguments are required.

    >>> UTCDateTime(1970, 1, 1)
    UTCDateTime(1970, 1, 1, 0, 0)
    
    >>> UTCDateTime(1970, 1, 1, 12, 23, 34, 123456)
    UTCDateTime(1970, 1, 1, 12, 23, 34, 123456)
    
  5. Using the following keyword arguments: year, month, day, julday, hour, minute, second, microsecond. Either the combination of year, month and day, or year and Julian day are required.

    >>> UTCDateTime(year=1970, month=1, day=1, minute=15, microsecond=20)
    UTCDateTime(1970, 1, 1, 0, 15, 0, 20)
    
    >>> UTCDateTime(year=2009, julday=234, hour=14, minute=13)
    UTCDateTime(2009, 8, 22, 14, 13)
    
  6. Using a Python datetime.datetime object.

    >>> dt = datetime.datetime(2009, 5, 24, 8, 28, 12, 5001)
    >>> UTCDateTime(dt)
    UTCDateTime(2009, 5, 24, 8, 28, 12, 5001)
    

Precision

The UTCDateTime class works with a default precision of 6 digits which effects the comparison of date/time values, e.g.:

>>> dt = UTCDateTime(0)
>>> dt2 = UTCDateTime(0.00001)
>>> dt3 = UTCDateTime(0.0000001)
>>> print(dt.precision)
6
>>> dt == dt2  # 5th digit is within current precision
False
>>> dt == dt3  # 7th digit will be neglected
True

You may change that behavior either by,

  1. using the precision keyword during object initialization:

    >>> dt = UTCDateTime(0, precision=4)
    >>> dt2 = UTCDateTime(0.00001, precision=4)
    >>> print(dt.precision)
    4
    >>> dt == dt2
    True
    
  2. or set it the class attribute DEFAULT_PRECISION for all new UTCDateTime objects using a monkey patch:

    >>> UTCDateTime.DEFAULT_PRECISION = 4
    >>> dt = UTCDateTime(0)
    >>> dt2 = UTCDateTime(0.00001)
    >>> print(dt.precision)
    4
    >>> dt == dt2
    True
    

    Don’t forget to reset DEFAULT_PRECISION if not needed anymore!

    >>> UTCDateTime.DEFAULT_PRECISION = 6
    

Attributes

DEFAULT_PRECISION int(x=0) -> integer
__dict__
__doc__ str(object=’‘) -> str
__module__ str(object=’‘) -> str
__weakref__ list of weak references to the object (if defined)
date Returns a Python date object..
datetime Returns a Python datetime object.
day Returns day as an integer.
hour Returns hour as an integer.
julday Returns Julian day as an integer.
microsecond Returns microseconds as an integer.
minute Returns minute as an integer.
month Returns month as an integer (January is 1, December is 12).
precision Returns precision of current UTCDateTime object.
second Returns seconds as an integer.
time Returns a Python time object.
timestamp float(x) -> floating point number
weekday Return the day of the week as an integer (Monday is 0, Sunday is 6).
year Returns year of the current UTCDateTime object.

Public Methods

ctime Return a string representing the date and time.
dst Returns None (to stay compatible with datetime.datetime)
formatArcLink DEPRECATED: ‘formatArcLink’ has been renamed to
formatFissures DEPRECATED: ‘formatFissures’ has been renamed to
formatIRISWebService DEPRECATED: ‘formatIRISWebService’ has been renamed to
formatSEED DEPRECATED: ‘formatSEED’ has been renamed to
formatSeedLink DEPRECATED: ‘formatSeedLink’ has been renamed to
format_arclink Returns string representation for the ArcLink protocol.
format_fissures Returns string representation for the IRIS Fissures protocol.
format_iris_web_service Returns string representation usable for the IRIS Web services.
format_seed Returns string representation for a SEED volume.
format_seedlink Returns string representation for the SeedLink protocol.
isocalendar Returns a tuple containing (ISO year, ISO week number, ISO weekday).
isoformat Return a string representing the date and time in ISO 8601 format.
isoweekday Return the day of the week as an integer (Monday is 1, Sunday is 7).
now Returns current UTC datetime.
strftime Return a string representing the date and time, controlled by an explicit format string.
strptime Return a UTCDateTime corresponding to date_string, parsed according to
timetuple Return a time.struct_time such as returned by time.localtime().
timetz Return time object with same hour, minute, second, microsecond, and tzinfo attributes.
toordinal Return proleptic Gregorian ordinal. January 1 of year 1 is day 1.
tzname Returns None (to stay compatible with datetime.datetime)
utcnow Returns current UTC datetime.
utcoffset Returns None (to stay compatible with datetime.datetime)
utctimetuple Return a time.struct_time of current UTCDateTime object.

Private Methods

Warning

Private methods are mainly for internal/developer use and their API might change without notice.

_from_datetime Use Python datetime object to set current time.
_get_date Returns a Python date object..
_get_datetime Returns a Python datetime object.
_get_day Returns day as an integer.
_get_hour Returns hour as an integer.
_get_hours_after_midnight Calculate foating point hours after midnight.
_get_julday Returns Julian day as an integer.
_get_microsecond Returns microseconds as an integer.
_get_minute Returns minute as an integer.
_get_month Returns month as an integer (January is 1, December is 12).
_get_precision Returns precision of current UTCDateTime object.
_get_second Returns seconds as an integer.
_get_time Returns a Python time object.
_get_timestamp Returns UTC timestamp in seconds.
_get_weekday Return the day of the week as an integer (Monday is 0, Sunday is 6).
_get_year Returns year of the current UTCDateTime object.
_parse_iso_8601 Parses an ISO8601:2004 date time string.
_repr_pretty_
_set Sets current timestamp using kwargs.
_set_day Sets day of current UTCDateTime object.
_set_hour Sets hours of current UTCDateTime object.
_set_julday Sets Julian day of current UTCDateTime object.
_set_microsecond Sets microseconds of current UTCDateTime object.
_set_minute Sets minutes of current UTCDateTime object.
_set_month Sets month of current UTCDateTime object.
_set_precision Set precision of current UTCDateTime object.
_set_second Sets seconds of current UTCDateTime object.
_set_year Sets year of current UTCDateTime object.

Special Methods

__abs__ Returns absolute timestamp value of the current UTCDateTime object.
__add__ Adds seconds and microseconds to current UTCDateTime object.
__dir__ default dir() implementation
__eq__ Rich comparison operator ‘==’.
__float__ Returns UTC timestamp in seconds.
__format__ default object formatter
__ge__ Rich comparison operator ‘>=’.
__gt__ Rich comparison operator ‘>’.
__hash__ An object is hashable if it has a hash value which never changes during its lifetime.
__init__ Creates a new UTCDateTime object.
__le__ Rich comparison operator ‘<=’.
__lt__ Rich comparison operator ‘<’.
__ne__ Rich comparison operator ‘!=’.
__new__ Create and return a new object.
__reduce__ helper for pickle
__reduce_ex__ helper for pickle
__repr__ Returns a representation of UTCDatetime object.
__sizeof__ size of object in memory, in bytes
__str__ Returns ISO8601 string representation from current UTCDateTime object.
__sub__ Subtracts seconds and microseconds from current UTCDateTime object.
__subclasshook__ Abstract classes can override this to customize issubclass().
__unicode__ Returns ISO8601 unicode representation from current UTCDateTime object.