A Year and a Day in Old Theradane by Scott Lynch
After a night of drinking and playing cards with her former gang is interrupted by the chaos caused by the feuding of two wizards that rule the city, famed thief Amarelle Parathis decides to drunkenly berate one of the said wizards. The next morning the wizard replays a threat Amarelle made the night before, which could get her killed or worse. To save herself, Amarelle agrees to destroy the focal point of another wizard's power in the titular time frame. Getting help from her roguish gang of thieves, they race to save Amarelle's existence in full knowledge that if they succeed it won't be the end of their work for the wizard.