function iterDatespace( start, stop, N, options ) {
	var step;
	var iter;
	var opts;
	var rfcn;
	var FLG;
	var t1;
	var t2;
	var n;
	var d;
	var i;

	t1 = convert( start );
	if ( t1 instanceof Error ) {
		throw t1;
	}
	t2 = convert( stop );
	if ( t2 instanceof Error ) {
		throw t2;
	}
	opts = {
		'round': DEFAULT_ROUNDING_MODE
	};
	if ( arguments.length === 3 ) {
		if ( isNonNegativeInteger( N ) ) {
			n = N;
		} else if ( isPlainObject( N ) ) {
			n = DEFAULT_LENGTH;
			if ( hasOwnProp( N, 'round' ) ) {
				if ( !contains( ROUNDING_MODES, N.round ) ) {
					throw new TypeError( format( 'invalid option. Unrecognized rounding mode. Option: `%s`.', N.round ) );
				}
				opts.round = N.round;
			}
		} else {
			throw new TypeError( format( 'invalid argument. Third argument must be either a nonnegative integer or an options object. Value: `%s`.', N ) );
		}
	} else if ( arguments.length > 3 ) {
		if ( !isNonNegativeInteger( N ) ) {
			throw new TypeError( format( 'invalid argument. Third argument must be a nonnegative integer. Value: `%s`.', N ) );
		}
		n = N;
		if ( !isPlainObject( options ) ) {
			throw new TypeError( format( 'invalid argument. Fourth argument must be an object. Value: `%s`.', options ) );
		}
		if ( hasOwnProp( options, 'round' ) ) {
			if ( !contains( ROUNDING_MODES, options.round ) ) {
				throw new TypeError( format( 'invalid option. Unrecognized rounding mode. Option: `%s`.', options.round ) );
			}
			opts.round = options.round;
		}
	} else {
		n = DEFAULT_LENGTH;
	}
	rfcn = ROUNDING_FCNS[ opts.round ];
	d = n - 1;
	step = (t2-t1) / d;
	i = -1;

	// Create an iterator protocol-compliant object:
	iter = {};
	setReadOnly( iter, 'next', next );
	setReadOnly( iter, 'return', end );

	// If an environment supports `Symbol.iterator`, make the iterator iterable:
	if ( iteratorSymbol ) {
		setReadOnly( iter, iteratorSymbol, factory );
	}
	return iter;

	/**
	* Returns an iterator protocol-compliant object containing the next iterated value.
	*
	* @private
	* @returns {Object} iterator protocol-compliant object
	*/
	function next() {
		i += 1;
		if ( FLG || i >= n ) {
			return {
				'done': true
			};
		}
		if ( i === 0 ) {
			return {
				'value': new Date( t1 ),
				'done': false
			};
		}
		if ( i === d ) {
			return {
				'value': new Date( t2 ),
				'done': false
			};
		}
		return {
			'value': new Date( rfcn( t1+(i*step) ) ),
			'done': false
		};
	}

	/**
	* Finishes an iterator.
	*
	* @private
	* @param {*} [value] - value to return
	* @returns {Object} iterator protocol-compliant object
	*/
	function end( value ) {
		FLG = true;
		if ( arguments.length ) {
			return {
				'value': value,
				'done': true
			};
		}
		return {
			'done': true
		};
	}

	/**
	* Returns a new iterator.
	*
	* @private
	* @returns {Iterator} iterator
	*/
	function factory() {
		return iterDatespace( start, stop, n, opts );
	}
}
Returns an iterator which returns evenly spaced dates over a specified interval.

@param {(NonNegativeInteger|string|Date)} start - starting date as either a `Date` object, JavaScript timestamp, or a date string (inclusive)
@param {(NonNegativeInteger|string|Date)} stop - stopping date as either a `Date` object, JavaScript timestamp, or a date string (inclusive)
@param {NonNegativeInteger} [N=100] - number of values
@param {Options} [options] - function options
@param {string} [options.round='floor'] - specifies how sub-millisecond times should be rounded: 'floor', 'ceil', or 'round'
@throws {TypeError} a numeric `start` argument must be a nonnegative integer
@throws {TypeError} a numeric `stop` argument must be a nonnegative integer
@throws {TypeError} unable to parse date string
@throws {TypeError} `N` argument must be a nonnegative integer
@throws {TypeError} `options` argument must be an object
@throws {TypeError} must provide valid options
@returns {Iterator} iterator

@example
var MILLISECONDS_IN_DAY = require( '@stdlib/constants/time/milliseconds-in-day' );

var start = new Date();
var iter = iterDatespace( start, new Date( start.getTime()+MILLISECONDS_IN_DAY ) );

var v = iter.next().value;
// returns <Date>

v = iter.next().value;
// returns <Date>

v = iter.next().value;
// returns <Date>

// ...