Context :

Aims : Since the last phase coherent timing solution of the nearby radio-quiet isolated neutron star RX J0720.4 $ - $ 3125 six new XMM-Newton and three Chandra observations were carried out .
The phase coherent timing solutions from previous authors were performed without restricting to a fixed energy band .
However , we recently showed that the phase residuals are energy dependent , and thus phase coherent solutions must be computed referring always to the same energy band .

Methods : We updated the phase coherent timing solution for RX J0720.4 $ - $ 3125 by including the recent XMM-Newton EPIC-pn , MOS1 , MOS2 and Chandra ACIS data in the energy range 400-1000 eV .
Altogether these observations cover a time span of almost 10 yrs .
A further timing solution was obtained including the ROSAT pointed data .
In this case , observations cover a time span of \approx 16 yrs .
To illustrate the timing differences between the soft band ( 120-400 eV ) and the hard band ( 400-1000 eV ) a timing solution for the soft band is also presented and the results are verified using a \mathrm { Z _ { n } ^ { 2 } } test .

Results : In contrast to previous work , we obtain almost identical solutions whether or not we include the ROSAT or Chandra data .
Thanks to the restriction to the hard band , the data points from EPIC-pn are in better agreement with those from MOS1 , MOS2 and Chandra than in previous works .
In general the phase residuals are still large and vary with time .
In particular , the latest XMM-Newton and Chandra data show that the phase residuals have attained relatively large and negative values .
Using this and previous timing solutions , the residuals indicate a cyclic behaviour with a period \mathrm { \approx 7 - 9 \leavevmode \nobreak yrs } if the variations follow a sinusoid , or twice this value in case the residuals are modulated by an abs ( sine ) probably approaching a new minimum around MJD=55000 days ( September 2009 ) .
As an alternative interpretation , the phase residuals can be fitted with a glitch that occured around MJD=53000 days .

Conclusions :