step
Specifies the legal number intervals for an <input> element. For example: if step="3", legal numbers could be -3, 0, 3, 6, etc. The step attribute can be used together with the max and min properties to create a range of legal values. The step property works with the following input types: number, range, date, datetime, datetime-local, month, time and week.
Note: most browsers will default this value to 1. This has the effect of making fractional values invalid. If you are using browser validation and need to allow fractional values, set this to 'any'.
Default value
Blank - no step specified.
Valid values
Any numeric value or 'any'.