matlab\timefun – Функции времени и даты
Current date and time
<now> - Current date and time as date number.
NOW Current date and time as date number.
T = NOW returns the current date and time as a serial date
number.
FLOOR(NOW) is the current date and REM(NOW,1) is the current time.
DATESTR(NOW) is the current date and time as a string.
See also date, datenum, datestr, clock.
Reference page in Help browser
doc now
<date> - Current date as date string.
DATE Current date as date string.
S = DATE returns a string containing the date in dd-mmm-yyyy format.
See also now, clock, datenum.
Reference page in Help browser
doc date
<clock> - Current date and time as date vector.
CLOCK Current date and time as date vector.
C = CLOCK returns a six element date vector containing the current time
and date in decimal form:
[year month day hour minute seconds]
The sixth element of the date vector output (seconds) is accurate to
several digits beyond the decimal point. FIX(CLOCK) rounds to integer
display format.
Note: When timing the duration of an event, use the TIC and TOC
functions instead of CLOCK or ETIME. These latter two functions are
based on the system time which can be adjusted periodically by the
operating system and thus might not be reliable in time comparison
operations.
See also datevec, datenum, now, etime, tic, toc, cputime.
Reference page in Help browser
doc clock
Basic functions
<datenum> - Serial date number.
DATENUM Serial date number.
N = DATENUM(V) converts one or more date vectors V into serial date
numbers N. Input V can be an M-by-6 or M-by-3 matrix containing M full
or partial date vectors respectively. DATENUM returns a column vector
of M date numbers.
A date vector contains six elements, specifying year, month, day, hour,
minute, and second. A partial date vector has three elements, specifying
year, month, and day. Each element of V must be a positive double
precision number. A serial date number of 1 corresponds to Jan-1-0000.
The year 0000 is merely a reference point and is not intended to be
Interpreted as a real year.
N = DATENUM(S,F) converts one or more date strings S to serial date
numbers N using format string F. S can be a character array where each
row corresponds to one date string, or one dimensional cell array of
strings. DATENUM returns a column vector of M date numbers, where M is the number of strings in S.
All of the date strings in S must have the same format F, which must be
composed of date format symbols according to Table 2 in DATESTR help.
Formats with 'Q' are not accepted by DATENUM.
Certain formats may not contain enough information to compute a date
number. In those cases, hours, minutes, and seconds default to 0, days
default to 1, months default to January, and years default to the
current year. Date strings with two character years are interpreted to
be within the 100 years centered around the current year.
N = DATENUM(S,F,P) or N = DATENUM(S,P,F) uses the specified format F and the pivot year P to determine the date number N, given the date string S. The pivot year is the starting year of the 100-year range in which a two-character year resides. The default pivot year is the current year minus 50 years.
N = DATENUM(Y,MO,D) and N = DATENUM([Y,MO,D]) return the serial date numbers for corresponding elements of the Y,MO,D (year,month,day)
arrays. Y, MO, and D must be arrays of the same size (or any can be a
scalar).
N = DATENUM(Y,MO,D,H,MI,S) and N =DATENUM([Y,MO,D,H,MI,S]) return the serial date numbers for corresponding elements of the Y,MO,D,H,MI,S (year,month,day,hour,minute,second) arrays. The six arguments must be arrays of the same size (or any can be a scalar).
N = DATENUM(S) converts the string or date vector (as defined by
DATEVEC) S into a serial date number. If S is a string, it must be in
one of the date formats 0,1,2,6,13,14,15,16,23 as defined by DATESTR.
This calling syntax is provided for backward compatibility, and is
significantly slower than the syntax which specifies the format string.
If the format is known, the N = DATENUM(S,F) syntax should be used.
N = DATENUM(S,P) converts the date string S, using pivot year P. If the
format is known, the N = DATENUM(S,F,P) or N = DATENUM(S,P,F) syntax should be used.
Note: The vectorized calling syntax can offer significant performance
improvement for large arrays.
Examples:
n = datenum('19-May-2000') returns n = 730625.
n = datenum(2001,12,19) returns n = 731204.
n = datenum(2001,12,19,18,0,0) returns n = 731204.75.
n = datenum('19.05.2000','dd.mm.yyyy') returns n = 730625.
See also now, datestr, datevec, datetick.
Reference page in Help browser
doc datenum
<datestr> - String representation of date.
DATESTR String representation of date.
S = DATESTR(V) converts one or more date vectors V to date strings S.
Input V must be an M-by-6 matrix containing M full (six-element) date
vectors. Each element of V must be a positive double-precision number.
DATESTR returns a column vector of M date strings, where M is the total
number of date vectors in V.
S = DATESTR(N) converts one or more serial date numbers N to date
strings S. Input argument N can be a scalar, vector, or
multidimensional array of positive double-precision numbers. DATESTR
returns a column vector of M date strings, where M is the total number
of date numbers in N.
S = DATESTR(D, F) converts one or more date vectors, serial date
numbers, or date strings D into the same number of date strings S.
Input argument F is a format number or string that determines the
format of the date string output. Valid values for F are given in Table
1, below. Input F may also contain a free-form date format string
consisting of format tokens as shown in Table 2, below.
Date strings with 2-character years are interpreted to be within the
100 years centered around the current year.
S = DATESTR(S1, F, P) converts date string S1 to date string S,
applying format F to the output string, and using pivot year P as the
starting year of the 100-year range in which a two-character year
resides. The default pivot year is the current year minus 50 years.
F = -1 uses the default format.
S = DATESTR(...,'local') returns the string in a localized format. The
default (which can be called with 'en_US') is US English. This argument
must come last in the argument sequence.
Note: The vectorized calling syntax can offer significant performance
improvement for large arrays.
Table 1: Standard MATLAB Date format definitions
Number String Example
===========================================================
0 'dd-mmm-yyyy HH:MM:SS' 01-Mar-2000 15:45:17
1 'dd-mmm-yyyy' 01-Mar-2000
2 'mm/dd/yy' 03/01/00
3 'mmm' Mar
4 'm' M
5 'mm' 03
6 'mm/dd' 03/01
7 'dd' 01
8 'ddd' Wed
9 'd' W
10 'yyyy' 2000
11 'yy' 00
12 'mmmyy' Mar00
13 'HH:MM:SS' 15:45:17
14 'HH:MM:SS PM' 3:45:17 PM
15 'HH:MM' 15:45
16 'HH:MM PM' 3:45 PM
17 'QQ-YY' Q1-96
18 'QQ' Q1
19 'dd/mm' 01/03
20 'dd/mm/yy' 01/03/00
21 'mmm.dd,yyyy HH:MM:SS' Mar.01,2000 15:45:17
22 'mmm.dd,yyyy' Mar.01,2000
23 'mm/dd/yyyy' 03/01/2000
24 'dd/mm/yyyy' 01/03/2000
25 'yy/mm/dd' 00/03/01
26 'yyyy/mm/dd' 2000/03/01
27 'QQ-YYYY' Q1-1996
28 'mmmyyyy' Mar2000
29 (ISO 8601) 'yyyy-mm-dd' 2000-03-01
30 (ISO 8601) 'yyyymmddTHHMMSS' 20000301T154517
31 'yyyy-mm-dd HH:MM:SS' 2000-03-01 15:45:17
Table 2: Free-form date format symbols
Symbol Interpretation of format symbol
===========================================================
yyyy full year, e.g. 1990, 2000, 2002
yy partial year, e.g. 90, 00, 02
mmmm full name of the month, according to the calendar locale, e.g.
"March", "April" in the UK and USA English locales.
mmm first three letters of the month, according to the calendar
locale, e.g. "Mar", "Apr" in the UK and USA English locales.
mm numeric month of year, padded with leading zeros, e.g. ../03/..
or ../12/..
m capitalized first letter of the month, according to the
calendar locale; for backwards compatibility.
dddd full name of the weekday, according to the calendar locale, e.g.
"Monday", "Tuesday", for the UK and USA calendar locales.
ddd first three letters of the weekday, according to the calendar
locale, e.g. "Mon", "Tue", for the UK and USA calendar locales.
dd numeric day of the month, padded with leading zeros, e.g.
05/../.. or 20/../..
d capitalized first letter of the weekday; for backwards
compatibility
HH hour of the day, according to the time format. In case the time
format AM | PM is set, HH does not pad with leading zeros. In
case AM | PM is not set, display the hour of the day, padded
with leading zeros. e.g 10:20 PM, which is equivalent to 22:20;
9:00 AM, which is equivalent to 09:00.
MM minutes of the hour, padded with leading zeros, e.g. 10:15,
10:05, 10:05 AM.
SS second of the minute, padded with leading zeros, e.g. 10:15:30,
10:05:30, 10:05:30 AM.
FFF milliseconds field, padded with leading zeros, e.g.
10:15:30.015.
PM set the time format as time of morning or time of afternoon. AM
or PM is appended to the date string, as appropriate.
Examples:
DATESTR(now) returns '24-Jan-2003 11:58:15' for that particular date,
on an US English locale DATESTR(now,2) returns 01/24/03, the same as
for DATESTR(now,'mm/dd/yy') DATESTR(now,'dd.mm.yyyy') returns
24.01.2003 To convert a non-standard date form into a standard MATLAB
dateform, first convert the non-standard date form to a date number,
using DATENUM, for example,
DATESTR(DATENUM('24.01.2003','dd.mm.yyyy'),2) returns 01/24/03.
See also date, datenum, datevec, datetick.
Reference page in Help browser
doc datestr
<datevec> - Date components.
DATEVEC Date components.
V = DATEVEC(N) converts one or more date numbers N to date vectors V. N can be a scalar, vector, or multidimensional array of positive date numbers. DATEVEC returns an M-by-6 matrix containing M date vectors, where M is the total number of date numbers in N.
V = DATEVEC(S,F) converts one or more date strings S to date vectors
V using format string F to interpret the date strings in S. S can be a
cell array of strings or a character array where each row corresponds
to one date string. All of the date strings in S must have the same
format which must be composed of date format symbols according to
Table 2 in DATESTR help. Formats with 'Q' are not accepted by DATEVEC.
DATEVEC returns an M-by-6 matrix of date vectors, where M is the number of date strings in S.
Certain formats may not contain enough information to compute a date
vector. In those cases, hours, minutes, and seconds default to 0, days
default to 1, months default to January, and years default to the
current year. Date strings with two character years are interpreted to
be within the 100 years centered around the current year.
V = DATEVEC(S,F,P) or V = DATEVEC(S,P,F) converts the date string S to a date vector V, using the pivot year P and the date format F. The pivot year is the starting year of the 100-year range in which a two-character year resides. The default pivot year is the current year minus 50 years.
[Y,MO,D,H,MI,S] = DATEVEC(...) takes any of the two syntaxes shown
above and returns the components of the date vector as individual
variables.
V = DATEVEC(S) converts date string S to date vector V. S must be in
one of the date formats 0,1,2,6,13,14,15,16,23 as defined by DATESTR.
This calling syntax is provided for backward compatibility, and is
significantly slower than the syntax which specifies the format string.
If the format is known, the V = DATEVEC(S,F) syntax should be used.
V = DATEVEC(S,P) converts the date string S using pivot year P.
If the format is known, the V = DATEVEC(S,F,P) or V = DATEVEC(S,P,F)
syntax should be used.
Note 1: If more than one input argument is used, the first argument
must be a date string or array of date strings.
Note 2: The vectorized calling syntax can offer significant performance
improvement for large arrays.
Examples
d = '12/24/1984';
t = 725000.00;
c = datevec(d) or c = datevec(t) produce c = [1984 12 24 0 0 0].
[y,m,d,h,mi,s] = datevec(d) returns y=1984, m=12, d=24, h=0, mi=0, s=0.
c = datevec('5/6/03') produces c = [2003 5 6 0 0 0] until 2054.
c = datevec('5/6/03',1900) produces c = [1903 5 6 0 0 0].
c = datevec('19.05.2000','dd.mm.yyyy') produces c = [2000 5 19 0 0 0].
See also datenum, datestr, clock, datetick.
Reference page in Help browser
doc datevec