Q:

whereBetween eloquent query returns empty output

I'm trying to use 'whereBetween' eloqouent query with two given start and end dates.
$first_day_this_month = date('Y-m-01 H:s:i'); //get the first day of the current month
$yesterDay = date('Y-m-d H:s:i',strtotime("-1 days")); //get yesterday's date

$d = m_chat_history::where('employee_id',$request->other_id)
                ->whereNull('to_group')->where('to_employee_id',$request->id)
                ->whereBetween('created_at',[$yesterDay,$first_day_this_month])
                ->get();

I make sure I have all the required data for the query by 'var_dump' and it did gives me all the required data needed for the query but the query returns me an empty output. Any ideas, clues, suggestions, help, recommendations please? I tried to remove the 'whereBetween' and my query works like it returns me the expected output but with 'whereBetween', the return output is empty.

A:

Make sure to use the same type and format as created_at when defining the values for whereBetween. As you're using datetime you could define edge values like (just one of many ways of doing it):
$first_day_this_month = date('Y-m-01 H:i:s');
$yesterday = date('Y-m-d H:i:s', strtotime("-1 day"));

Also make sure of the order of params (still please consider edge cases like first day of the month where $yesterday would be smaller, so you have to add some logic and be careful):
->whereBetween('created_at', [$first_day_this_month, $yesterday])

Edit: wasn't timestamp...

