def df_addts(df):
    """ this bloc generate a timestep sequence for psuedo real-time simulation """
    mod = list(df['Unnamed: 0'])
    tiempo = 0
    ts = []
    for i, v in enumerate(mod[:-1]):
        ts.append(tiempo)
        if mod[i + 1] < mod[i]:
            tiempo += 30
        else:
            continue
    ts.append(ts[-1])
    df.loc[:, ('ts')] = ts
    return df
