File Dates
File Time Options
File Times
PAMGuard will attempt to automatically derive a date and time from audio file names. While we have programmed in a large number of different time and date formats, we cannot capture them all so it’s sometimes necessary to tell PAMGuard exactly how to extract date and time information from a file name. Characters (a-z) and be stripped automatically, but problems arise if other numbers are present.
An example of names that can’t be unpacked automatically might be
1677738025.180912073628.d24.d8.wav
The actual date is 12 September 2018 at 07:36:28. however it is impossible for PAMGuard to work out that the date information is between the second and third ‘.’ characters and that the rest of the name should be ignored.
To define your own file format, select ‘User defined date format’ then in the format field, enter a set of characters that will tell PAMGuard how to unpack the information.
For every character in the file name that is NOT part of the date, enter the # character. The number of # must exactly match the number of characters preceding the date part of the name. Leading and trailing non numeric characters will also be stripped automatically after characters corresponding to a # have been removed.
For the date section, Java lays down strict rules for how each character should be represented details of which are here and below. Note that most of these are case sensitive, e.g. MM is for month and mm is for minute.
Letter
Date or Time Component
Presentation
Examples
G
Era designator
AD
y
Year
1996; 96
Y
Week year
2009; 09
M
Month in year (context sensitive)
July; Jul; 07
L
Month in year (standalone form)
July; Jul; 07
w
Week in year
27
W
Week in month
2
D
Day in year
189
d
Day in month
10
F
Day of week in month
2
E
Day name in week
Tuesday; Tue
u
Day number of week (1 = Monday, …, 7 = Sunday)
1
a
Am/pm marker
PM
H
Hour in day (0-23)
0
k
Hour in day (1-24)
24
K
Hour in am/pm (0-11)
0
h
Hour in am/pm (1-12)
12
m
Minute in hour
30
s
Second in minute
55
S
Millisecond
978
z
Time zone
Pacific Standard Time; PST; GMT-08:00
Z
Time zone
-0800
X
Time zone
-08; -0800; -08:00
The example below shows an appropriate date format string used to correctly unpack the above example file name
Time Zone
Ideally, all PAMGuard data should be referenced to UTC, this makes it easy to align with GPS data and data from other sources.
Sometimes, it is necessary to process audio files which do not have a UTC based time encoded in their file name, but are referenced to some other time zone.
The File Date Settings dialog allows you to set the time zone and any additional time offsets for an audio file or set of audio files.
The time zone offset and optional daylight saving will be SUBTRACTED from the time value extracted from the file name.
The additional time offset will be ADDED to the time value extracted from the file name.
Check and double check that the time extracted from the file and corrected for time zone and offset is correct before processing sound file data.