  We present an empirical test indicating that the mean I-band magnitude of the
red clump stars, used as the standard candle in the recent distance
determinations to the Magellanic Clouds and other objects, is age independent
for intermediate age (2-10 Gyr) stars. Fifteen star clusters of age ~1.5-12 Gyr
from the LMC and SMC (ESO121SC03, SL663, NGC2155, NGC2121, SL388, SL862,
NGC121, L1, KRON3, NGC416, L113, NGC339, L11, NGC419, NGC411) were observed and
their color-magnitude diagrams are presented. The mean I-band brightness of the
red clump in these clusters is constant and its mean extinction-free magnitude
is: I_0=17.88+/-0.05 mag and I_0=18.31+/-0.07 mag at the mean metallicity of
-0.8 dex and -1.2 dex for the LMC and SMC clusters, respectively. For older
objects (> 10 Gyr) the brightness of the red clump, which converts into the red
part of the horizontal branch, fades by about 0.3-0.4 mag, setting an important
limitation on the red clump stars method of distance determination.
  The red clump distance moduli to the Magellanic Clouds from the new
independent data set are: m-M=18.18+/-0.06 mag and m-M=18.65+/-0.08 mag for the
LMC and SMC, respectively, in very good agreement with previous determinations.
  Weak dependence of the mean I-band brightness of the red clump on metallicity
and its independence of age for intermediate age population (2-10 Gyr) of stars
as well as the most precise calibration as compared to other standard candle
candidates makes the red clump stars method one of the most accurate steps in
the distance scale ladder.
