A bcron expression describes how often a payment should happen. Optionally it can also include start and end-time limits.

## Examples

`/1000` |
=> | repeat the payment every 1000 blocks |

`:750000/1` |
=> | repeat the payment every block, until blockheight 750000 |

`740000/15` |
=> | repeat the payment every 15 blocks, starting at blockheight 740000 |

## Full spec

```
From Until Frequency BCron
--------------------------
- - - n Only once, at block n
- - 1 /1 Every block
- - n /n Every block which is a multiple of n
x - 1 x/1 Every block starting from x
x - n x/n Every n blocks from x (x, x+n, x+2n, ..)
- y 1 :y/1 Every block until y
- y n :y/n Every n blocks until y (.., y-2n, y-n, y)
x y 1 x:y/1 Every block starting from x until y
x y n x:y/n Every n blocks starting from x until y (x, x+n, x+2n, .. x+in <= y)
```

When `from`

is specified, the ticks count relative to `from`

.

When `from`

isn't specified, but `until`

is, the ticks count relative to `until`

. For example, for `:200/3`

, the ticks are (.., 194, 197, 200).