How to get Epoch/UNIX timestamps in Ruby

In Ruby, getting Epoch timestamps is straightforward, and there are several methods to accomplish this task. This article explores different ways to get Epoch timestamps in Ruby and provides practical use cases.

Using the Time.now Method

Ruby provides a built-in Time class that includes the now method for fetching the current time as an Epoch timestamp. This method returns the current timestamp as a floating-point number.

epoch_time = Time.now.to_i
puts "Current Epoch timestamp: \#{epoch_time}"

In this code snippet, the Time.now.to_i method is used to obtain the current Epoch timestamp, and then it's displayed.

Use Case 1: Logging timestamps

data = "Sensor data reading..."
epoch_time = Time.now.to_i
log_entry = "\#{data} - timestamp: \#{epoch_time}"
puts log_entry

In this example, we use the Time.now.to_i method to record a timestamp along with sensor data. It's a common practice for logging data with timestamps for reference.

Use Case 2: Time Duration Calculation

start_time = Time.now.to_i

# Perform a task or operation

end_time = Time.now.to_i

time_elapsed = end_time - start_time
puts "Time taken: \#{time_elapsed} seconds"

In this use case, we record the start and end times in Time.now.to_i to measure the time taken for a task. The difference between the end time and start time gives the time duration.

Using the Time.at Method

The Time.at method in Ruby allows you to create a Time object from an Epoch timestamp. You can then convert this object back to an Epoch timestamp.

epoch_time = Time.at(1635283800)
puts "Epoch timestamp: \#{epoch_time.to_i}"

In this code, we use the Time.at method to create a Time object from the given Epoch timestamp and then convert it back to an Epoch timestamp in to_i.

Use Case 3: Expiry timestamp for Cache

cache = {}
cache_key = "cached_data"
expiry_time = Time.now + 600 # 10 minutes from now

cache[cache_key] = "Cached data that expires at \#{expiry_time.to_i}"

current_time = Time.now

if current_time.to_i > expiry_time.to_i
  puts "Cache expired. Recaching data..."
  # Re-cache the data
end

In this example, we calculate the expiry time for cache data by adding 600 seconds (10 minutes) to the current time and use to_i to convert the Time objects to Epoch timestamps.

Use Case 4: Event Scheduling

event_time = Time.now + 3600 # 1 hour from now

loop do
  current_time = Time.now
  if current_time >= event_time
    puts "Event occurred!"
    break
  else
    sleep(60) # Check every minute
  end
end

The Time class is employed to schedule an event to occur in the future. In this case, we add 3600 seconds (1 hour) to the current time to set the event time.

These code examples demonstrate how to get Epoch/UNIX timestamps in Ruby and showcase their applications in practical scenarios. Whether you need to log data with timestamps, calculate time durations, set cache expiry times, or schedule events, Epoch timestamps are versatile tools in Ruby for precise time-related operations.