This mod uses a script to allow you to choose the time period in game hours when Vampires should be considered to be in sunlight ("TOD" is short for "time of day"). It adds a simple MCM menu with two sliders - 'Sunrise' and 'Sunset' - that determine when the 'Weakness to Sunlight' debuff should be added and when it should be removed (as well as when to play the "Your vampire blood boils in the sunlight" effect).

What this mod does:
Allows you to choose when to take the sun debuff as a Vampire.

What this mod does not do:
Change the actual time of day when the sun rises/sets.

What this mod affects:
- All four levels of sun debuff
- Vampire Lord sun debuff
- Mist Form stamina regeneration (apparently this is a thing, according to CK)
- Sun debuff of NPC Vampires

What this mod does not affect:
- Sanguinare Vampiris progression
- The time of day when you are able use the special effect of Auriel's Bow (orignal author didn't know how this works in detail at the time and didn't want to break anything)

This mod is for those who wish to tweak when Vampires take the sun debuff to match lighting changes related to the sunrise and sunset from lighting mods or ENBs, or even without them. It was originally made for those who play with ENB presets that modify the TOD (time of day), such as the sunrise as it can be immersion-breaking when the game tells you that your vampire blood boils in the sunlight but it's still dark out as far as the eye is concerned. The mod could also be used as a means to tweak the game's difficulty as well, if that's what you're after. I personally use it to set the sun debuff to take place between 6 am - 7 pm (instead of the vanilla 5 am - 7 pm), as I've felt 5 am is too early.

Installation:
Install via your mod manager but backup your save first to come back to in case you wish to uninstall it later as this mod contains a script

Uninstallation:
Uninstall via your mod manager and ideally return to your backup save

Note:
The original author expressed potential plans to make an SE port and add more features to the mod but also that it may never happen. That was in 2017 and there have been no updates since. Based on the original page, they've given permission to port it and use it in other mods as long as they're credited. I've decided to port it since I like the mod and for others on SE to be able to find more easily if it's something they're looking for. If the author decides to take up the reigns on this mod again, I'd be happy to give it back to them.

Link to the original mod: VTOD - Adjust Vampire Sun Damage TODs
Pop over and endorse!

Links to my other Vampire-related ports:
TDN Vampire Armor Retexture SE Port
Strong Vampiric Drain by Aedred SE Port

Compatibility:
I'm unsure if this mod is compatible with Vampire overhauls that affect the sun debuff or damage taken by the player since I don't use any. The original author didn't specify it either on their page. I'm not able to thoroughly test this with popular overhauls at the moment either. In theory, this mod should be placed after any Vampire overhauls in the load order. If anyone is willing to give feedback based on testing or experience with other Vampire overhauls, feel free to let me know in the posts section or via Nexus DMs. Feel free to make patches as necessary.

"As you know, vampires are powerful, but we have limits. Our great enemy is the sun, and until recently it's an enemy we've had no way to fight." - Lord Harkon

Credits:

TheS0m3b0dy for creating the original mod and script