1Period(3)             User Contributed Perl Documentation            Period(3)
2
3
4

NAME

6       Time::Period - A Perl module to deal with time periods.
7

SYNOPSIS

9       "use Time::Period;"
10
11       "$result = inPeriod($time, $period);"
12

DESCRIPTION

14       The inPeriod function determines if a given time falls within a given
15       period.  inPeriod returns 1 if the time does fall within the given
16       period, 0 if not, and -1 if inPeriod detects a malformed time or
17       period.
18
19       The time is specified as per the "time()" function, which is assumed to
20       be the number of non-leap seconds since January 1, 1970.
21
22       The period is specified as a string which adheres to the format
23
24               sub-period[, sub-period...]
25
26       or the string "none" or whitespace.  The string "none" is not case
27       sensitive.
28
29       If the period is blank, then any time period is assumed because the
30       time period has not been restricted.  In that case, inPeriod returns 1.
31       If the period is "none", then no time period applies and inPeriod
32       returns 0.
33
34       A sub-period is of the form
35
36               scale {range [range ...]} [scale {range [range ...]}]
37
38       Scale must be one of nine different scales (or their equivalent codes):
39
40               Scale  | Scale | Valid Range Values
41                      | Code  |
42               *******|*******|************************************************
43               year   |  yr   | n     where n is an integer 0<=n<=99 or n>=1970
44               month  |  mo   | 1-12  or  jan, feb, mar, apr, may, jun, jul,
45                      |       |           aug, sep, oct, nov, dec
46               week   |  wk   | 1-6
47               yday   |  yd   | 1-365
48               mday   |  md   | 1-31
49               wday   |  wd   | 1-7   or  su, mo, tu, we, th, fr, sa
50               hour   |  hr   | 0-23  or  12am 1am-11am 12noon 12pm 1pm-11pm
51               minute |  min  | 0-59
52               second |  sec  | 0-59
53
54       The same scale type may be specified multiple times.  Additional scales
55       simply extend the range defined by previous scales of the same type.
56
57       The range for a given scale must be a valid value in the form of
58
59               v
60
61       or
62
63               v-v
64
65       For the range specification v-v, if the second value is larger than the
66       first value, the range wraps around unless the scale specification is
67       year.
68
69       Year does not wrap because the year is never really reset, it just
70       increments.  Ignoring that fact has lead to the dreaded year 2000
71       nightmare.  When the year rolls over from 99 to 00, it has really
72       rolled over a century, not gone back a century.  inPeriod supports the
73       dangerous two digit year notation because it is so rampant.  However,
74       inPeriod converts the two digit notation to four digits by prepending
75       the first two digits from the current year.  In the case of 99-1972,
76       the 99 is translated to whatever current century it is (probably 20th),
77       and then range 99-1972 is treated as 1972-1999.  If it were the 21st
78       century, then the range would be 1972-2099.
79
80       Anyway, if v-v is 9-2 and the scale is month, September, October,
81       November, December, January, and February are the months that the range
82       specifies.  If v-v is 2-9, then the valid months are February, March,
83       April, May, Jun, July, August, and September.  9-2 is the same as Sep-
84       Feb.
85
86       v isn't a point in time.  In the context of the hour scale, 9 specifies
87       the time period from 9:00:00 am to 9:59:59 am.  This is what most
88       people would call 9-10.  In other words, v is discrete in its time
89       scale.  9 changes to 10 when 9:59:59 changes to 10:00:00, but it is 9
90       from 9:00:00 to 9:59:59.  Just before 9:00:00, v was 8.
91
92       Note that whitespace can be anywhere and case is not important.  Note
93       also that scales must be specified either in long form (year, month,
94       week, etc.) or in code form (yr, mo, wk, etc.).  Scale forms may be
95       mixed in a period statement.
96
97       Furthermore, when using letters to specify ranges, only the first two
98       for week days or the first three for months are significant.  January
99       is a valid specification for jan, and Sunday is a valid specification
100       for su.  Sun is also valid for su.
101
102   PERIOD EXAMPLES
103       To specify a time period from Monday through Friday, 9am to 5pm, use a
104       period such as
105
106               wd {Mon-Fri} hr {9am-4pm}
107
108       When specifing a range by using -, it is best to think of - as meaning
109       through.  It is 9am through 4pm, which is just before 5pm.
110
111       To specify a time period from Monday through Friday, 9am to 5pm on
112       Monday, Wednesday, and Friday, and 9am to 3pm on Tuesday and Thursday,
113       use a period such as
114
115               wd {Mon Wed Fri} hr {9am-4pm}, wd{Tue Thu} hr {9am-2pm}
116
117       To specify a time period that extends Mon-Fri 9am-5pm, but alternates
118       weeks in a month, use a period such as
119
120               wk {1 3 5} wd {Mon Wed Fri} hr {9am-4pm}
121
122       Or how about a period that specifies winter?
123
124               mo {Nov-Feb}
125
126       This is equivalent to the previous example:
127
128               mo {Jan-Feb Nov-Dec}
129
130       As is
131
132               mo {jan feb nov dec}
133
134       And this is too:
135
136               mo {Jan Feb}, mo {Nov Dec}
137
138       Wait!  So is this:
139
140               mo {Jan Feb} mo {Nov Dec}
141
142       To specify a period that describes every other half-hour, use something
143       like
144
145               minute { 0-29 }
146
147       To specify the morning, use
148
149               hour { 12am-11am }
150
151       Remember, 11am is not 11:00:00am, but rather 11:00:00am - 11:59:59am.
152
153       Hmmmm, 5 second blocks could be a fun period...
154
155               sec {0-4 10-14 20-24 30-34 40-44 50-54}
156
157       To specify every first half-hour on alternating week days, and the
158       second half-hour the rest of the week, use the period
159
160               wd {1 3 5 7} min {0-29}, wd {2 4 6} min {30-59}
161

VERSION

163       1.20
164

HISTORY

166               Version 1.20
167               ------------
168                       - Added the ability to specify no time period.
169
170               Version 1.13
171               ------------
172                       - Cleaned up the error checking code.
173
174               Version 1.12
175               ------------
176                       - Updated email and web space information.
177
178               Version 1.11
179               ------------
180                       - Minor bug fix in 1.10.
181
182               Version 1.10
183               ------------
184                       - Released.
185

AUTHOR

187       Patrick Ryan <pgryan@geocities.com>
188
190       Copyright (c) 1997 Patrick Ryan.  All rights reserved.  This Perl
191       module uses the conditions given by Perl.  This module may only be
192       distributed and or modified under the conditions given by Perl.
193

DATE

195       August 26, 1997
196

SOURCE

198       This distribution can be found at
199
200               http://www.geocities.com/SiliconValley/Lakes/8456/
201
202       or
203
204               http://www.perl.com/CPAN/modules/by-module/Time/
205
206
207
208perl v5.12.0                      1997-08-27                         Period(3)
Impressum