You can play around with the custom format in the appropriate recording profile.
The default is $c/$t%F%R$-e$n.$x, which expands to:
Channel_name/Event_titleDate_in_ISO_format24_hr_time-partial_file_number.extension
From the documentation:
> The format strings $t,$s,%e,$c also have delimiter variants such as $ t (space after the dollar character), $-t, $_t, $.t, $,t, $;t. In these cases, the delimiter is applied only when the substituted string is not empty.
In other words, changing $-e in the string to, say, $ e should give you a space delimiter instead of a hyphen. Similarly, you can try simply inserting spaces, e.g. %F %R to separate the date and time, or %F_%R to avoid spaces (which can confuse things for some applications/OSes).