Company: DAWN
Filing Date: 2025-04-11
Form Type: DEF 14A
Source: 0001140361-25-013462
Chunk: 9

Company: Day One Biopharmaceuticals, Inc.
Filing Date: 2025-04-11
Form: DEF 14A
Chunk 9
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 www.virtualshareholdermeeting.com/DAWN2025. |     | You may vote by telephone or through the Internet-in order to do so, please follow the instructions shown on your proxy card. |     | You may vote by mail-if you request or receive a paper proxy card and voting instructions by mail, simply complete, sign and date the enclosed proxy card and promptly return it in the envelope provided or, if the envelope is missing, please mail your completed proxy card to Vote Processing, c/o Broadridge, 51 Mercedes Way, Edgewood, New York 11717. Your completed, signed, and dated proxy card must be received prior to the Annual Meeting. |

Votes submitted by telephone or through the Internet must be received by 11:59 p.m. Eastern Time on June 1, 2025. Submitting your proxy, whether by telephone, through the Internet or, if you request or receive a paper proxy card, by mail will not affect your right to vote in person should you decide to attend the Annual Meeting. If you are not the stockholder of record, please refer to the voting instructions provided by your nominee to direct your nominee on how to vote your shares. Your vote is important. Whether or not you plan to attend the Annual Meeting, we urge you to vote by proxy to ensure that your vote is counted. All proxies will be voted in accordance with the instructions specified on the proxy card. If you sign a physical proxy card and return it without instructions as to how your shares should be voted on a particular proposal at the Annual Meeting, your shares will be voted in accordance with the recommendations of our board of directors stated above.

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If you do not vote and you hold your shares in street name, and your broker does not have discretionary power to vote your shares, your shares may constitute “broker non-votes” (as described above) and will not be counted in determining the number of shares necessary for approval of the proposals. However, broker non-votes will be counted for the purpose of establishing a quorum for the Annual Meeting. If you receive more than one proxy card, your shares are registered in more than one name or are registered in different accounts. To make certain all of your shares are voted, please follow the instructions included on each proxy card and vote each proxy card by telephone, through the Internet or by mail. If you requested or received paper proxy materials and you intend to vote by mail, please complete, sign and return each proxy card you received