I wrote a patch against zabbix 1.4.1. These are the changes I made:

• included the fix I send you earlier today (typo in calculating the
  seconds for one week in frontends/php/include/services.inc.php)
• added a new drop-down box to srv_status.php which lets you choose the
  period for which the "IT SERVICES" page is generated. It showed always
  "last 7 days" while most people are using "this month" as SLA Parameter.
  Now you can choose between today, this week, this month, this year, last
  24 hours, last 7 days, last 30 days and last 365 days.
• included translations for english and german

The other translations are missing, sorry.

I think you know that you can apply the patch running:

patch -p1 < ../sla-reporting.patch

if you are inside the toplevel directory of the zabbix source and the
patch is located one dir up.

The patch is attached.