Net income per share is computed by dividing net income by the daily weighted average number of common shares outstanding during the applicable periods. Diluted net income per share includes the potentially dilutive effect of common shares subject to outstanding stock options and restricted stock awards using the treasury stock method. Under the treasury stock method, shares subject to certain outstanding stock options and restricted stock awards have been excluded from the diluted weighted average shares outstanding calculation because the exercise of those options or the vesting of those restricted stock awards would lead to a net reduction in common shares outstanding. As a result, stock options and restricted stock awards to acquire 22,065 and 100,196 weighted common shares have been excluded from the diluted weighted shares outstanding for the three-month periods ended September 30, 2018 and 2017, respectively, and 64,041 and 132,247 weighted common shares have been excluded from the diluted weighted shares outstanding for the nine-month periods ended September 30, 2018 and 2017, respectively.

A reconciliation of net income per share is as follows (in thousands, except per share data):

	Three-Month Periods Ended September 30,				Nine-Month Periods Ended September 30,
	2018		2017		2018		2017

Numerator:
Net income	$	851	$	870	$	1,345	$	1,390
Denominator:
Weighted average common shares outstanding		5,212		5,138		5,200		5,117
Dilutive potential common shares		32		13		6		4
Shares used in diluted net income per common share calculations		5,244		5,151		5,206		5,121
Basic net income per common share	$	0.16	$	0.17	$	0.26	$	0.27
Diluted net income per common share	$	0.16	$	0.17	$	0.26	$	0.27