1Period(3)             User Contributed Perl Documentation            Period(3)
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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 sen‐
27       sitive.
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, No‐
81       vember, 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
84       Sep-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 peo‐
88       ple would call 9-10.  In other words, v is discrete in its time scale.
89       9 changes to 10 when 9:59:59 changes to 10:00:00, but it is 9 from
90       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
104       To specify a time period from Monday through Friday, 9am to 5pm, use a
105       period such as
106
107               wd {Mon-Fri} hr {9am-4pm}
108
109       When specifing a range by using -, it is best to think of - as meaning
110       through.  It is 9am through 4pm, which is just before 5pm.
111
112       To specify a time period from Monday through Friday, 9am to 5pm on Mon‐
113       day, Wednesday, and Friday, and 9am to 3pm on Tuesday and Thursday, use
114       a period such as
115
116               wd {Mon Wed Fri} hr {9am-4pm}, wd{Tue Thu} hr {9am-2pm}
117
118       To specify a time period that extends Mon-Fri 9am-5pm, but alternates
119       weeks in a month, use a period such as
120
121               wk {1 3 5} wd {Mon Wed Fri} hr {9am-4pm}
122
123       Or how about a period that specifies winter?
124
125               mo {Nov-Feb}
126
127       This is equivalent to the previous example:
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129               mo {Jan-Feb Nov-Dec}
130
131       As is
132
133               mo {jan feb nov dec}
134
135       And this is too:
136
137               mo {Jan Feb}, mo {Nov Dec}
138
139       Wait!  So is this:
140
141               mo {Jan Feb} mo {Nov Dec}
142
143       To specify a period that describes every other half-hour, use something
144       like
145
146               minute { 0-29 }
147
148       To specify the morning, use
149
150               hour { 12am-11am }
151
152       Remember, 11am is not 11:00:00am, but rather 11:00:00am - 11:59:59am.
153
154       Hmmmm, 5 second blocks could be a fun period...
155
156               sec {0-4 10-14 20-24 30-34 40-44 50-54}
157
158       To specify every first half-hour on alternating week days, and the sec‐
159       ond half-hour the rest of the week, use the period
160
161               wd {1 3 5 7} min {0-29}, wd {2 4 6} min {30-59}
162

VERSION

164       1.20
165

HISTORY

167               Version 1.20
168               ------------
169                       - Added the ability to specify no time period.
170
171               Version 1.13
172               ------------
173                       - Cleaned up the error checking code.
174
175               Version 1.12
176               ------------
177                       - Updated email and web space information.
178
179               Version 1.11
180               ------------
181                       - Minor bug fix in 1.10.
182
183               Version 1.10
184               ------------
185                       - Released.
186

AUTHOR

188       Patrick Ryan <pgryan@geocities.com>
189
191       Copyright (c) 1997 Patrick Ryan.  All rights reserved.  This Perl mod‐
192       ule uses the conditions given by Perl.  This module may only be dis‐
193       tributed and or modified under the conditions given by Perl.
194

DATE

196       August 26, 1997
197

SOURCE

199       This distribution can be found at
200
201               http://www.geocities.com/SiliconValley/Lakes/8456/
202
203       or
204
205               http://www.perl.com/CPAN/modules/by-module/Time/
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208
209perl v5.8.8                       1997-08-26                         Period(3)
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