The computational components of basic and diluted earnings per share for the three months ended September 30, 2023 and 2022 are as follows:


	Three months ended September 30,
(in thousands)	2023		2022
Numerator (for basic and diluted earnings per share)
Net income attributable to CECO Environmental Corp.	$	3,330	$	1,943

Denominator
Basic weighted-average shares outstanding		34,772		34,456
Common stock equivalents arising from stock options and restricted stock awards		529		415
Diluted weighted-average shares outstanding		35,301		34,871

The computational components of basic and diluted earnings per share for the nine months ended September 30, 2023 and 2022 are as follows:


	Nine months ended September 30,
(in thousands)	2023		2022
Numerator (for basic and diluted earnings per share)
Net income attributable to CECO Environmental Corp.	$	9,032	$	9,122

Denominator
Basic weighted-average shares outstanding		34,612		34,791
Common stock equivalents arising from stock options and restricted stock awards		604		244
Diluted weighted-average shares outstanding		35,216		35,035

Options and restricted stock units included in the computation of diluted earnings per share are calculated using the treasury stock method. For the three months ended September 30, 2023 and 2022, zero and 1.2 million, respectively, and for the nine months ended September 30, 2023 and 2022, 0.7 million and 1.7 million, respectively, of outstanding options and restricted stock units were excluded from the computation of diluted earnings per share due to their anti-dilutive effect.

Once a restricted stock unit vests, it is included in the computation of weighted average shares outstanding for purposes of basic and diluted earnings per share.

On May 10, 2022, the Company's Board of Directors authorized a share repurchase program under which the Company may purchase up to $20.0 million of its outstanding shares of common stock through April 30, 2025. The authorization permits the Company to repurchase shares in the open market, through accelerated share repurchases, block trades, Rule 10b5-1 trading plans or through privately negotiated transactions in accordance with applicable laws, rules and regulations. Under the program, the Company repurchased zero and 256,000 shares at a cost of zero and $2.2 million during the three months ended September 30, 2023 and 2022, respectively, and zero and 981,000 shares at a cost of zero and $6.5 million during the nine months ended September 30, 2023 and 2022, respectively.