I am allowed 1200 calories per day..any tips on a sweet, low calorie, late night snack?

A piece of hard candy lasts a while.

yogurt with honey

Medifast makes some GREAT high-protein (11g/serving) low-carb (>16 g/serving) products that are around 100 calories. Examples are: Soft Bake Brownies, Soft Bake Chocolate Chip Cookies, Cinnamon Pretzels, Soft Serve Ice Cream in Mango, Peanut Butter or Chocolate Mint, many flavors of Crunchy or Chewy Bars, Hot Cocoa, Cappuchino, Chai Latte, Soft Bake Gingerbread, etc. I use these at night for a late-night treat and they fit in perfectly with my macros!

Sometimes I buy things like little ice lollies and little ice creams for something to have at night. Mini milks for example only have 30 calories in one and they take longer than other snacks to eat as well, and there's plenty of other similar ice lollies that are under 100 calories.

You could also have a yoghurt. I've started buying strawberry muller light yoghurts, they're only 99 calories each and you get a lot for 99 calories.

You could also have some frozen yoghurt - it has a less calories than ice cream and is fruity and sweet.

You could also buy fruits like pineapple which tend to be sweeter than apples/grapes/oranges. Or you could make a little fruit salad with or without yoghurt.

Those are the little sweet treats that I like to have, I tend to avoid chocolate as it isn't really satisfying in small quantities in my opinion.

Frozen grapes- they're sweet and just like popsicles!

TUNNOCKS TEA CAKES.
If you're in the US I hope you can get them there. They're from Scotland.

They're incredible AND only 105 calories!

They are like chocolate-covered marshmallow biscuits, but they're also veggie because the mallow is from Italian meringue and doesn't contain any gelatine.

sliced apples with a teaspoon of peanut butter on the side.

fat free / sugar free jello made with diet Sprite / orange pop / sparking flavored water, etc. = 20 calories for the entire serving, and it's a lot. Enjoy.

I think Dannon's dairy dessert cheesecakes are delicious and they're only 180 calories.

Frozen blueberries, frozen grapes

Light N' Fit makes great greek yogurt flavors for only 80 cals (have a caramel apple pie one to die for). Plus I've heard of people mixing those frosting creations packs in with vanilla or unflavored greek yogurt.

Fiber One makes a Cocoa cereal 80 calories for 3/4 cup

VitaBrownies only 50 cals or double chocolate vitatop 100 cals

Sweet freedom makes these fudge delites fudge pops only 35 cals each

You can get no sugar added pie fillings only 30-40 cals per 1/3 cup. Heat up in microwave sooooo good. Can even top with fiber one cereal or crumble a graham cracker.
I even like to put the apple pie on inside a corn tortilla on my George Foreman. It's like a mexican sopapilla.

low fat popcorn
greek yogurt
cheese string
sunflower seeds
apple slices w/tbsp peanut butter
grapes, raspberries, strawberries w/cool whip or light whipped cream
melba toast rounds with tsp/tbsp peanut butter
fresh veggies with tbsp favorite dip

Frozen cool whip
Jelly
Berries
Low cal hot chocolate
Skinny Cow ice cream sandwiches
Popsicles
Frozen Chobani

I use to go for low fat, sugar free things, but they always replace natural ingredients for sweeteners that just trick your body into wanting more. If you choose small amounts of things that aren't fake, you will actually eat less of it and be satisfied. For sweets, I usually eat anything i want, just in small amounts. I suggest small amounts of dark chocolate, a cup of hot chocolate, fruit, greek yogurt, frozen yogurt, or save up some of you calories from the day and use it splurge once in awhile after dinner. It's a lifestyle change, not a diet , just remember that.

sugar free jello 10 calories the strawberry is the best!