🕒Cronslab

An advanced redstone scheduler block with a similar syntax to cron. See Usage for a heavily detailed overview, or Examples for a quick start.

Crafting

Usage

Right click to open the GUI and input the expression. The GUI contains a "to English" translator of the given expression, but this is also gone over below.

Fields

A cronslab is made up of four fields representing ticks, seconds, minutes, and minecraft days. Each describes which value of that field's interval the signal should be active.

There are some extra rules for this different to cron, but have been made in a way that tries to 'make sense' for Minecraft, and doesn't need consideration. See Quirks.

Example:

The tick field has an interval of 20 (since 20 ticks = 1 second). So for the following values of the field:

0:     The 0th tick of every second.
*:     Every tick of every second.
*/4:   The 4th tick.
0-3:   0th to 3rd tick.
0-9/2: Every even tick between 0 and 9.

Fields can be a comma-separated list of values, which pass if any value passes (an OR expression):

5,6:    The 5th or 6th tick of.
*/2,15: Any even tick, or the 15th tick.

Expression

An expression is made of the four fields, where all must pass to emit a signal.

* 0-29 */2 *:  Constant for the first 30 seconds of the minute AND only every other minute.
0 0-5 * *:     Five 1-tick pulses a second apart every minute.

Quirks

There are two things that are worth noting for advanced use.

Gametime vs Daytime

Per the minecraft wiki:

There are [multiple] types of time:

• Gametime - The total number of game ticks that have elapsed in the world.

• Daylight cycle time (aka. internal daytime) - The total number of game ticks that have elapsed during the daylight cycle. It does not elapse when the game rule advance_time is false.

By default, the expression evaluator will operate on gametime. This counts from the world start, and isn't affected by the advance_time gamerule, but might not be synced to the visual day/night cycle. However, if the day field is relevant (i.e. not *), then the Cronslab will work on the daytime. This is synchronised with the visual day/night cycle, but will not update when advance_time is false.

Interval Extension

In normal cron you can't schedule, for example, every 45 minutes in a single expression. Cronslab gets around this by possibly extending the interval of a field when checked. The rules are meant be common sense, but for clarify:

• If the field is cyclical (a wildcard or unbounded range e.g. 4/2), then it's interval is multiplied by each field 'ahead' that has at least one wildcard value.

• Example: The ticks field in */15 * 0 * will have it's interval extended to 20 * 60 = 1200, which correctly spaces signals every 15 ticks.

• The days field has an effective infinite interval.