Missing data: era5-reanalysis-complete on model levels


When using the following script to download ERA5 model level data for a several day time period (to prepare WRF boundary conditions), the request completes without error but the resulting NetCDF file is missing 2 days worth of data (between 2018-04-25 and 2018-04-26) while data is present for the 24 and 26-27 of April 2018. 

I've tested this for two other time periods and a similar problem occurs. Any idea what may be the issue in my script or in general? 

Thank you for any help,

import cdsapi

start_date = '2018-04-24'
end_date = '2018-04-27'
c = cdsapi.Client()
file_name = f"ERA5-{start_date}-{end_date}-ML.nc"
model_level_params = {
    "class": "ea",
    "expver": "1",
    "levelist": "1/to/137",
    "levtype": "ml",
    "param": "129/130/131/132/133",
    "stream": "oper",
    "type": "an",
    "format": "netcdf",
    "date": f"{start_date}/{end_date}",
    "area": "60/250/0.0/340",
    "time": "00:00:00/to/23:00:00/by/1",
    "grid": "1.0/1.0", # NOTE CHANGE TO 0.25 to 0.25
c.retrieve("reanalysis-era5-complete", model_level_params, file_name)