Why are you so hostile?

Dont know the exact code section of DC law, but I trust OTA.

This is from OTA's guide here

Tenant’s Notice of Intent to Vacate: The Act clarifies existing law regarding the tenant notice of intent to vacate the unit during a month-to-month tenancy. A housing provider may not require a month-to-month tenant to give more than a 30-day notice of his or her intent to vacate the unit. The tenant should be aware, however, that the notice does not take effect until 30 days after the date that the rent is next due. For example, if a tenant’s notice of intent to vacate the unit is given to the housing provider on February 15th, and the rent is next due on March 1st, then the tenancy will not terminate until April 1.

The law is somewhat different for a tenant who wishes to move out upon the expiration of the written lease term, i.e., before the tenancy becomes month-to month. In that instance, the lease may require more than 30 days-notice of a tenant’s intent to vacate, but only if the lease also entitles the tenant to a written notice of a rent increase that is at least 15 days longer than that. For example, if the lease requires the tenant to provide a 60-day notice of intent to vacate, the lease must also entitle the tenant to a 75-day notice of a rent increase. If the lease fails to do so, the tenant is only required to give the housing provider a 30-day notice of intent to vacate.

D.C. Code 42-3505.54 (b)

Make sure to read til the end of the section. (It's a single sentence, so I'm confident you can manage.)