Best evidence so far is that it can survive for up to 5 days outside the host. How long it can survive exposes to UV depends on a number of factors. There is a reason they use level 4 precautions and not just UV lights.
http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/ebola-eng.php
Public Health Agency of Canada
PATHOGEN SAFETY DATA SHEET - INFECTIOUS SUBSTANCES SECTION I
- INFECTIOUS AGENT NAME: Ebola virus
INFECTIOUS DOSE: 1 - 10 aerosolized organisms are sufficient to cause infection in humans (21).
MODE OF TRANSMISSION: In an outbreak, it is hypothesized that the first patient becomes infected as a result of contact with an infected animal (15). Person-to-person transmission occurs via close personal contact with an infected individual or their body fluids during the late stages of infection or after death (1, 2, 15, 27). Nosocomial infections can occur through contact with infected body fluids due to the reuse of unsterilized syringes, needles, or other medical equipment contaminated with these fluids (1, 2). Humans may be infected by handling sick or dead non-human primates and are also at risk when handling the bodies of deceased humans in preparation for funerals, suggesting possible transmission through aerosol droplets (2, 6, 28). In the laboratory, infection through small-particle aerosols has been demonstrated in primates, and airborne spread among humans is strongly suspected, although it has not yet been conclusively demonstrated (1, 6, 13). The importance of this route of transmission is not clear. Poor hygienic conditions can aid the spread of the virus (6).
INCUBATION PERIOD: Two to 21 days, more often 4 - 9 days (1, 13, 14).
COMMUNICABILITY: Communicable as long as blood, secretions, organs, or semen contain the virus. Ebola virus has been isolated from semen 61 days after the onset of illness, and transmission through semen has occurred 7 weeks after clinical recovery
SUSCEPTIBILITY TO DISINFECTANTS: Ebola virus is susceptible to sodium hypochlorite, lipid solvents, phenolic disinfectants, peracetic acid, methyl alcohol, ether, sodium deoxycholate, 2% glutaraldehyde, 0.25% Triton X-100, β-propiolactone, 3% acetic acid (pH 2.5), formaldehyde and paraformaldehyde, and detergents such as SDS (20, 21, 31-34).
PHYSICAL INACTIVATION: Ebola are moderately thermolabile and can be inactivated by heating for 30 minutes to 60 minutes at 60ºC, boiling for 5 minutes, gamma irradiation (1.2 x106 rads to 1.27 x106 rads), and/or UV radiation
SURVIVAL OUTSIDE HOST: The virus can survive in liquid or dried material for a number of days (23). Infectivity is found to be stable at room temperature or at 4°C for several days, and indefinitely stable at -70°C (6, 20). Infectivity can be preserved by lyophilisation.
Could you give us a link to the site which says five days?