You have to set the argument field with the date mask!
M3U name is: 2017-07-25.m3u
The date part in the file is 2017-07-25
Date mask is: Y-m-d in the argument field (used separator is - a dash)
Note, this/it must be according to the PHP date().
Set in the argument field:
Don't forget the file extension.
The php date() is:
d Day of the month, 2 digits with leading zeros 01 to 31
D A textual representation of a day, three letters Mon through Sun
j Day of the month without leading zeros 1 to 31
m Numeric representation of a month, with leading zeros 01 through 12
n Numeric representation of a month, without leading zeros 1 through 12
Y A full numeric representation of a year, 4 digits Examples: 1999 or 2003
y A two digit representation of a year Examples: 99 or 03
Having a deeper understanding explained of programming in php!
Well this is not the intention.
Just a little bit of knowledge is enough, as showed in the list.
How the date mask works.
Also possible is a file name and hour like: morning_(2017-07-25)10.m3u
The mask will be: morning_(Y-m-d)H.m3u
a Lowercase Ante meridiem and Post meridiem am or pm
A Uppercase Ante meridiem and Post meridiem AM or PM
B Swatch Internet time 000 through 999
g 12-hour format of an hour without leading zeros 1 through 12
G 24-hour format of an hour without leading zeros 0 through 23
h 12-hour format of an hour with leading zeros 01 through 12
H 24-hour format of an hour with leading zeros 00 through 23
i Minutes with leading zeros 00 to 59
s Seconds, with leading zeros 00 through 59
u Microseconds (added in PHP 5.2.2).
Note that date() will always generate 000000 since it takes an integer parameter,
whereas DateTime::format() does support microseconds if DateTime was created with microseconds.
v Milliseconds (added in PHP 7.0.0). Same note applies as for u.