Do not check for leap year with modulo.

NoModuloForLeapYear.ql

/**
 * @name Do not check leap year using modulo
 * @description Use the system functions to check for leap years instead of modulo. Very low precision.
 * @kind problem
 * @tags reliability
 *       maintainability
 * @problem.severity recommendation
 * @sub-severity low
 * @precision low
 * @id py/no-leap-check-with-modulo
 */
import python

from BinaryExpr  expr
where 
	expr.getRight().(IntegerLiteral).getValue() = 4 and
	exists(Operator o | o = expr.getOp() and o.getSpecialMethodName() = "__mod__")
select expr, "It is possible that you are checking for a leap year with modulo. Use the `datetime` functions instead."