hydrograph timestamp issue for long-term simulation

[johnpark]

I am running a long-term hourly simulation (more than 50 years), and the output timestamps of the simulated hydrograph are shifted by milliseconds in the output file.
This happens sometime after 27 years and 10 months from the beginning.

13807.2,1977-10-20,04:00:00.00,0.949142,149.349,23.7861,290.09,32.8475,95.1431,6.2014,......
13807.2,1977-10-20,04:59:59.99,0.949142,148.218,23.7861,289.278,32.8475,94.9924,6.2014,......

Is there any way to prevent this? I want to have the correct hourly timestamp in the output file.

[rchlumsk]

Hi johnpark

This could be caused by the definition of the timestep in the rvt file, if you ensure that the definition of the timestep is defined as an exact fraction or timestep, i.e. 1:00:00 instead of 0.0416667 (=1/24), that should prevent the issue. You can try to play with the definition of the timestep and let me know if that helps the issue. My guess is that internally the timestep is defined to some number of decimal places (due to computational memory constraints) and the computational round off error doesn't show until after 27 years of hourly simulations.

If the timestep definition doesn't fix the issue, please post again and we can work to resolve it.

Cheers,
Rob