Test if a range intersects another range of numbers

Question

I have 2 range of numbers:

• $startTime to $endTime
• $offerStartTime to $offerEndTime

Answer 1

You can use range and array_intersect, i.e.:

function time_intersect($startTime, $endTime, $offerStartTime, $offerEndTime)
{
    $start_to_end = range($startTime, $endTime, 1);
    $offer_start_end = range($offerStartTime, $offerEndTime, 1);
    if (!empty(array_intersect($start_to_end, $offer_start_end)))
    {
      # time overlaps
      return true;
    }
}

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Explanation:

With range we create 2 arrays containing numbers based on the 4 variables (start, end), then we use array_intersect to check if the 2 arrays have numbers in common, if the output is not empty, we know the numbers (time) overlap.