Tvheadend

Not sure what settings you have, but mine uses local date/time and not UTC???

from the help:

Format string : The string allows you to manually specify the full path generation using predefined modifiers. See Help for full details. 
The string allows you to manually specify the full path generation using the predefined modifiers for strftime (see man strftime, except %n and %t) and Tvheadend specific. 
Note that you may modify some of this format string setting using the GUI fields below.

So I am guessing you can modify the string to whatever you like, but I have only used the basic %F and %R.

from manage:

man -P cat strftime
STRFTIME(3)                                                        Linux Programmer's Manual                                                        STRFTIME(3)

NAME
       strftime - format date and time

SYNOPSIS
       #include <time.h>

       size_t strftime(char *s, size_t max, const char *format,
                       const struct tm *tm);

DESCRIPTION
       The  strftime()  function formats the broken-down time tm according to the format specification format and places the result in the character array s of
       size max.

       The format specification is a null-terminated string and may contain special character sequences called conversion  specifications,  each  of  which  is
       introduced by a '%' character and terminated by some other character known as a conversion specifier character.  All other character sequences are ordi‐
       nary character sequences.

       The characters of ordinary character sequences (including the null byte) are copied verbatim from format to s.  However, the  characters  of  conversion
       specifications are replaced as follows:

       %a     The abbreviated name of the day of the week according to the current locale.

       %A     The full name of the day of the week according to the current locale.

       %b     The abbreviated month name according to the current locale.

       %B     The full month name according to the current locale.

       %c     The preferred date and time representation for the current locale.

       %C     The century number (year/100) as a 2-digit integer. (SU)

       %d     The day of the month as a decimal number (range 01 to 31).

       %D     Equivalent to %m/%d/%y.  (Yecch—for Americans only.  Americans should note that in other countries %d/%m/%y is rather common.  This means that in
              international context this format is ambiguous and should not be used.) (SU)

       %e     Like %d, the day of the month as a decimal number, but a leading zero is replaced by a space. (SU)

       %E     Modifier: use alternative format, see below. (SU)

       %F     Equivalent to %Y-%m-%d (the ISO 8601 date format). (C99)

       %G     The ISO 8601 week-based year (see NOTES) with century as a decimal number.  The 4-digit year corresponding to the ISO week number (see %V).  This
              has the same format and value as %Y, except that if the ISO week number belongs to the previous or next year, that year is used instead. (TZ)

       %g     Like %G, but without century, that is, with a 2-digit year (00-99). (TZ)

       %h     Equivalent to %b.  (SU)

       %H     The hour as a decimal number using a 24-hour clock (range 00 to 23).

       %I     The hour as a decimal number using a 12-hour clock (range 01 to 12).

       %j     The day of the year as a decimal number (range 001 to 366).

       %k     The hour (24-hour clock) as a decimal number (range 0 to 23); single digits are preceded by a blank.  (See also %H.)  (TZ)

       %l     The hour (12-hour clock) as a decimal number (range 1 to 12); single digits are preceded by a blank.  (See also %I.)  (TZ)

       %m     The month as a decimal number (range 01 to 12).

       %M     The minute as a decimal number (range 00 to 59).

       %n     A newline character. (SU)

       %O     Modifier: use alternative format, see below. (SU)

       %p     Either "AM" or "PM" according to the given time value, or the corresponding strings for the current locale.  Noon is treated as "PM" and midnight
              as "AM".

       %P     Like %p but in lowercase: "am" or "pm" or a corresponding string for the current locale. (GNU)

       %r     The time in a.m. or p.m. notation.  In the POSIX locale this is equivalent to %I:%M:%S %p.  (SU)

       %R     The time in 24-hour notation (%H:%M).  (SU) For a version including the seconds, see %T below.

       %s     The number of seconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC). (TZ)

       %S     The second as a decimal number (range 00 to 60).  (The range is up to 60 to allow for occasional leap seconds.)

       %t     A tab character. (SU)

       %T     The time in 24-hour notation (%H:%M:%S).  (SU)

       %u     The day of the week as a decimal, range 1 to 7, Monday being 1.  See also %w.  (SU)

       %U     The week number of the current year as a decimal number, range 00 to 53, starting with the first Sunday as the first day of week 01.  See also %V
              and %W.

       %V     The  ISO 8601 week number (see NOTES) of the current year as a decimal number, range 01 to 53, where week 1 is the first week that has at least 4
              days in the new year.  See also %U and %W.  (SU)

       %w     The day of the week as a decimal, range 0 to 6, Sunday being 0.  See also %u.

       %W     The week number of the current year as a decimal number, range 00 to 53, starting with the first Monday as the first day of week 01.

       %x     The preferred date representation for the current locale without the time.

       %X     The preferred time representation for the current locale without the date.

       %y     The year as a decimal number without a century (range 00 to 99).

       %Y     The year as a decimal number including the century.

       %z     The +hhmm or -hhmm numeric timezone (that is, the hour and minute offset from UTC). (SU)

       %Z     The timezone name or abbreviation.

       %+     The date and time in date(1) format. (TZ) (Not supported in glibc2.)

       %%     A literal '%' character.

       Some conversion specifications can be modified by preceding the conversion specifier character by the E or O modifier to indicate  that  an  alternative
       format should be used.  If the alternative format or specification does not exist for the current locale, the behavior will be as if the unmodified con‐
       version specification were used. (SU) The Single UNIX Specification mentions %Ec, %EC, %Ex, %EX, %Ey, %EY, %Od, %Oe, %OH, %OI, %Om, %OM, %OS, %Ou,  %OU,
       %OV, %Ow, %OW, %Oy, where the effect of the O modifier is to use alternative numeric symbols (say, roman numerals), and that of the E modifier is to use
       a locale-dependent alternative representation.

       The broken-down time structure tm is defined in <time.h>.  See also ctime(3).

RETURN VALUE
       Provided that the result string, including the terminating null byte, does not exceed max bytes, strftime() returns the number of bytes  (excluding  the
       terminating  null  byte)  placed  in the array s.  If the length of the result string (including the terminating null byte) would exceed max bytes, then
       strftime() returns 0, and the contents of the array are undefined.

       Note that the return value 0 does not necessarily indicate an error.  For example, in many locales %p yields an empty string.  An  empty  format  string
       will likewise yield an empty string.

ENVIRONMENT
       The environment variables TZ and LC_TIME are used.

CONFORMING TO
       SVr4,  C89,  C99.   There  are strict inclusions between the set of conversions given in ANSI C (unmarked), those given in the Single UNIX Specification
       (marked SU), those given in Olson's timezone package (marked TZ), and those given in glibc (marked GNU), except that %+ is not supported in glibc2.   On
       the  other  hand glibc2 has several more extensions.  POSIX.1 only refers to ANSI C; POSIX.2 describes under date(1) several extensions that could apply
       to strftime() as well.  The %F conversion is in C99 and POSIX.1-2001.

       In SUSv2, the %S specifier allowed a range of 00 to 61, to allow for the theoretical possibility of a minute that included a double leap  second  (there
       never has been such a minute).

NOTES
   ISO 8601 week dates
       %G, %g, and %V yield values calculated from the week-based year defined by the ISO 8601 standard.  In this system, weeks start on a Monday, and are num‐
       bered from 01, for the first week, up to 52 or 53, for the last week.  Week 1 is the first week where four or more days fall within the  new  year  (or,
       synonymously,  week 01 is: the first week of the year that contains a Thursday; or, the week that has 4 January in it).  When three of fewer days of the
       first calendar week of the new year fall within that year, then the ISO 8601 week-based system counts those days as part of week  53  of  the  preceding
       year.   For  example, 1 January 2010 is a Friday, meaning that just three days of that calendar week fall in 2010.  Thus, the ISO 8601 week-based system
       considers these days to be part of week 53 (%V) of the year 2009 (%G); week 01 of ISO 8601 year 2010 starts on Monday, 4 January 2010.

   Glibc notes
       Glibc provides some extensions for conversion specifications.  (These extensions are not specified in POSIX.1-2001, but a few other systems provide sim‐
       ilar  features.)   Between  the '%' character and the conversion specifier character, an optional flag and field width may be specified.  (These precede
       the E or O modifiers, if present.)

       The following flag characters are permitted:

       _      (underscore) Pad a numeric result string with spaces.

       -      (dash) Do not pad a numeric result string.

       0      Pad a numeric result string with zeros even if the conversion specifier character uses space-padding by default.

       ^      Convert alphabetic characters in result string to uppercase.

       #      Swap the case of the result string.  (This flag works only with certain conversion specifier characters, and of these, it is only  really  useful
              with %Z.)

       An optional decimal width specifier may follow the (possibly absent) flag.  If the natural size of the field is smaller than this width, then the result
       string is padded (on the left) to the specified width.

BUGS
       If the output string would exceed max bytes, errno is not set.  This makes it impossible to distinguish this error case  from  cases  where  the  format
       string legitimately produces a zero-length output string.  POSIX.1-2001 does not specify any errno settings for strftime().

       Some  buggy versions of gcc(1) complain about the use of %c: warning: `%c' yields only last 2 digits of year in some locales.  Of course programmers are
       encouraged to use %c, it gives the preferred date and time representation.  One meets all kinds of strange obfuscations to circumvent this gcc(1)  prob‐
       lem.  A relatively clean one is to add an intermediate function

           size_t
           my_strftime(char *s, size_t max, const char *fmt,
                       const struct tm *tm)
           {
               return strftime(s, max, fmt, tm);
           }

       Nowadays, gcc(1) provides the -Wno-format-y2k option to prevent the warning, so that the above workaround is no longer required.

EXAMPLE
       RFC 2822-compliant date format (with an English locale for %a and %b)

         "%a, %d %b %Y %T %z" 

       RFC 822-compliant date format (with an English locale for %a and %b)

         "%a, %d %b %y %T %z" 

   Example program
       The program below can be used to experiment with strftime().

       Some examples of the result string produced by the glibc implementation of strftime() are as follows:

           $ ./a.out '%m'
           Result string is "11" 
           $ ./a.out '%5m'
           Result string is "00011" 
           $ ./a.out '%_5m'
           Result string is "   11" 

   Program source
       #include <time.h>
       #include <stdio.h>
       #include <stdlib.h>

       int
       main(int argc, char *argv[])
       {
           char outstr[200];
           time_t t;
           struct tm *tmp;

           t = time(NULL);
           tmp = localtime(&t);
           if (tmp == NULL) {
               perror("localtime");
               exit(EXIT_FAILURE);
           }

           if (strftime(outstr, sizeof(outstr), argv[1], tmp) == 0) {
               fprintf(stderr, "strftime returned 0");
               exit(EXIT_FAILURE);
           }

           printf("Result string is \"%s\"\n", outstr);
           exit(EXIT_SUCCESS);
       }

SEE ALSO
       date(1), time(2), ctime(3), setlocale(3), sprintf(3), strptime(3)

COLOPHON
       This  page  is part of release 3.74 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the latest ver‐
       sion of this page, can be found at http://www.kernel.org/doc/man-pages/.

GNU                                                                        2014-08-19                                                               STRFTIME(3)

Thanks for that.

Weird. My logs are stamped in UTC too. Are yours? Obvious question, but I assume you aren't in the UK where local time would equal UTC...

Thanks for the extra bits. Not sure how I'd implement it in TVH though. Thoughts?

FYI, the problem ended up being the wrong timezone set in the Raspbian system.

Thanks again for your help everyone.