# Dumballah
[](https://travis-ci.org/ZuraGuerra/dumballah)
[](http://inch-ci.org/github/ZuraGuerra/dumballah)
[](https://beta.hexfaktor.org/github/ZuraGuerra/dumballah)
[](https://hex.pm/packages/dumballah)
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---
Dumballah is a tiny library that provides conversions between seconds and other time units, and some useful calculations to make easier the manipulation of Unix timestamps.
Dumballah is a voodoo Loa associated with the rain and the crops, that's why I chose his name for a library about time.
Here is the [documentation](https://hexdocs.pm/dumballah/api-reference.html).
## Requirements
Elixir 1.3+.
## Installation
Just add it to your `mix.exs` file:
```elixir
defp deps do
[{:dumballah, "~> 1.3"}]
end
```
## Usage
### Conversions
From `:hours`, `:days` and `:minutes` to seconds.
```elixir
Dumballah.Convert.to_seconds(:hours, 7)
> 25200
```
And viceversa.
```elixir
Dumballah.Convert.from_seconds(:hours, 25200)
> 7.0
```
### Calculations
Add and subtract `:hours`, `:days` and `:minutes` in seconds.
```elixir
Dumballah.now
|> Dumballah.Calculate.add_time(:days, 1)
> 1473962718
```
Identify passed timestamps.
```elixir
Dumballah.now
|> Dumballah.Calculate.has_passed?
> true
```
And more, like `date_from_dawn/1` and `seconds_until_midnight/1`: check the [docs](https://hexdocs.pm/dumballah/api-reference.html).
## Notes
`Dumballah.now/0` returns your current local time in seconds. If you need the current UTC time, use `DateTime.utc_now/0`, which is part of the Elixir standard library since 1.3.
## Recommended Readings
Working with date times is a [real](http://infiniteundo.com/post/25326999628/falsehoods-programmers-believe-about-time) [pain](http://infiniteundo.com/post/25509354022/more-falsehoods-programmers-believe-about-time); these links provide some insights on how the Erlang VM deals with time. You might find them useful.
[`calendar` module docs](http://erlang.org/doc/man/calendar.html)
[`os:timestamp/0` docs](http://erlang.org/doc/man/os.html#timestamp-0)
[`time/0` docs](http://erlang.org/doc/man/erlang.html#time-0)
[Time Correction in Erlang](http://erlang.org/doc/apps/erts/time_correction.html)
---
Sponsored by [steed.](http://steed.mx/)
