That bug has been opened on https://launchpad.net/distros/ubuntu/+source/evolution-data-server/+bug/35115

"From the description of time_from_isodate:

 * time_from_isodate:
 * @str: Date/time value in ISO 8601 format.
 *
 * Converts an ISO 8601 UTC time string into a time_t value.

However, it doesn't handle times, only dates:

With
#include <stdio.h>
#include <libecal/e-cal-time-util.h>

int main(int argc, char **argv) {
    printf("%d %s\n", time_from_isodate(argv[1]), argv[1]);
}

as our sample program, compiled using:

$ gcc $(pkg-config --libs --cflags libecal-1.2) test.c -o testt

We then get:

: tfheen@thosu /tmp > ./testt 20050601T010
-1 20050601T010
: tfheen@thosu /tmp > ./testt 20050601T010Z
-1 20050601T010Z
: tfheen@thosu /tmp >
...
Actually, this bug is bogus, since I forgot to include the seconds.

I think that time_from_isodate should be better at parsing the input, though and not require seconds."