diff --git a/src/diagnostics/Writers.jl b/src/diagnostics/Writers.jl
index 799b973c009..006a9b34456 100644
--- a/src/diagnostics/Writers.jl
+++ b/src/diagnostics/Writers.jl
@@ -4,6 +4,89 @@
 # writers come with opinionated defaults.
 
 
+"""
+    descriptive_name(sd_t::ScheduledDiagnosticTime)
+
+
+Return a compact, unique-ish, identifier for the given `ScheduledDiagnosticTime` `sd_t`.
+
+We split the period in seconds into days, hours, minutes, seconds. In most cases
+(with standard periods), this output will look something like
+`air_density_1d_max`. This function can be used for filenames.
+
+The name is not unique to the `ScheduledDiagnosticTime` because it ignores other
+parameters such as whether there is a reduction in space or the compute
+frequency.
+
+"""
+function descriptive_name(sd_t::ScheduledDiagnosticTime)
+    var = "$(sd_t.variable.short_name)"
+
+    isa_reduction = !isnothing(sd_t.reduction_time_func)
+
+    if isa_reduction
+        red = "$(sd_t.reduction_time_func)"
+
+        # Convert period from seconds to days, hours, minutes, seconds
+        period = ""
+
+        days, rem_seconds = divrem(sd_t.output_every, 24 * 60 * 60)
+        hours, rem_seconds = divrem(rem_seconds, 60 * 60)
+        minutes, seconds = divrem(rem_seconds, 60)
+
+        if days > 0
+            period *= "$(days)d_"
+        end
+        if hours > 0
+            period *= "$(hours)h_"
+        end
+        if minutes > 0
+            period *= "$(minutes)m_"
+        end
+        if seconds > 0
+            period *= "$(seconds)s_"
+        end
+
+        suffix = period * red
+    else
+        # Not a reduction
+        suffix = "inst"
+    end
+    return "$(var)_$(suffix)"
+end
+
+"""
+    descriptive_name(sd_i::ScheduledDiagnosticIterations, [Δt])
+
+
+Return a compact, unique-ish, identifier for the given
+`ScheduledDiagnosticIterations` `sd_i`.
+
+If the timestep `Δt` is provided, convert the steps into seconds. In this case,
+the output will look like `air_density_1d_max`. Otherwise, the output will look
+like `air_density_100it_max`. This function can be used for filenames.
+
+The name is not unique to the `ScheduledDiagnosticIterations` because it ignores
+other parameters such as whether there is a reduction in space or the compute
+frequency.
+
+"""
+function descriptive_name(sd_i::ScheduledDiagnosticIterations,
+                          Δt = nothing)
+
+    if !isnothing(Δt)
+        # Convert iterations into time
+        return descriptive_name(ScheduledDiagnosticTime(sd_i, Δt))
+    else
+        var = "$(sd_i.variable.short_name)"
+        suffix =
+            isnothing(sd_i.reduction_time_func) ? "inst" :
+            "$(sd_i.output_every)it_(sd_i.reduction_time_func)"
+        return "$(var)_$(suffix)"
+    end
+end
+
+
 """
     HDF5Writer()