By default this mod multiplies the days left for new daily quests and special orders by 2. You can set custom multipliers for each in the config.
Multipliers only affect new quests and special orders. For daily quests, "days left" is set when you accept the quest. For special orders (including Qi special orders), the "due date" is set at the beginning of the week regardless of when / if they are accepted or you even have the special orders boards unlocked.
If you set a multiplier to zero or less than zero, quests will never expire. At end of each day "days left" will not be decremented for daily quests and "due date" will be reset to the original value for special order quests.
Config
You can customize this mod by editing the config file or using Generic Mod Config Menu.
Technical
Requires SMAPI.
Implements a Generic Mod Config Menu interface to change config settings in-game.
Compatible with Mod Updater for automatic updates.
Code is at https://github.com/aedenthorn/StardewValleyMods.
If you want to complain or ask for help or help me test my mods, you can visit my Discord server.
A list of all my mods for Stardew Valley is available at https://www.curseforge.com/members/erinthe/projects.