I am using a dataset which is grouped by `group_by` function of `dplyr` package.
Each Group has it's own time index which i.e. supposedly consist of 12 months sequences.
This means that it can start from January and end up in December or in other cases it can start from June of the year before and end up in May next year.

Here is the dataset example:

```
     ID       DATE
      8 2017-01-31
      8 2017-02-28
      8 2017-03-31
      8 2017-04-30
      8 2017-05-31
      8 2017-06-30
      8 2017-07-31
      8 2017-08-31
      8 2017-09-30
      8 2017-10-31
      8 2017-11-30
      8 2017-12-31
     32 2017-01-31
     32 2017-02-28
     32 2017-03-31
     32 2017-04-30
     32 2017-05-31
     32 2017-06-30
     32 2017-07-31
     32 2017-08-31
     32 2017-09-30
     32 2017-10-31
     32 2017-11-30
     32 2017-12-31
     45 2016-09-30
     45 2016-10-31
     45 2016-11-30
     45 2016-12-31
     45 2017-01-31
     45 2017-02-28
     45 2017-03-31
     45 2017-04-30
     45 2017-05-31
     45 2017-06-30
     45 2017-07-31
     45 2017-08-31

```

The Problem is that I can't confirm or validate visualy because of dataset dimensions if there are so called "jumps", in other words if dates are consistent. Is there any simple way in r to do that, perhaps some modification/combination of functions from `tibbletime` package. 

Any help will by appreciated.

Thank you in advance.