Saul's example's are correct, but I'm afraid that the difference isn't about past and future.
'Since' is about a time period which began at a point in the past and is still continuing. This is why it is used with the perfect tenses.
However, 'until' is not only for the future. You can use it with any tense. For example, you would say -
Our meeting yesterday lasted until 10pm.
- which is clearly about past time.
Try thinking about it this way:
'Since' tells you when a time period started (from....)
'Until' tells you when a time period finished/finishes/will finish (to...)
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