diff --git a/lib/+artoa/+soundsources/calculateDrift.m b/lib/+artoa/+soundsources/calculateDrift.m
new file mode 100644
index 0000000000000000000000000000000000000000..bf2e80664a1341bcb0f393f7fb506d61f1545f50
--- /dev/null
+++ b/lib/+artoa/+soundsources/calculateDrift.m
@@ -0,0 +1,23 @@
+function [drift] = calculateDrift(pStartRafosDate, pEndRafosDate, pStartOffset, pEndOffset)
+%CALCULATEDRIFT Calculates the drift corresponding to 1 day.
+%   Calculates the drift of a soundsource in 1 day in seconds.
+%
+%   Parameters:
+%       pStartRafosDate (double):       The start rafos date that should be
+%                                       taken into account.
+%       pEndRafosDate (double):         The end rafos date.
+%       pStartOffset (double):          The starting offset [s].
+%       pEndOffset (double):            The end offset [s].
+%
+%   Returns:
+%       drift (double):     The calculated drift [s/day].
+
+%% Calculate drift
+duration = pEndRafosDate - pStartRafosDate;
+totalOffset = pEndOffset - pStartOffset;
+
+drift = totalOffset / duration;
+
+
+end
+
diff --git a/lib/+artoa/+soundsources/calculateToaAtTimestep.m b/lib/+artoa/+soundsources/calculateToaAtTimestep.m
new file mode 100644
index 0000000000000000000000000000000000000000..ad87af4f2cbdb541b41c8d443faf3dc642974d40
--- /dev/null
+++ b/lib/+artoa/+soundsources/calculateToaAtTimestep.m
@@ -0,0 +1,16 @@
+function [toa] = calculateToaAtTimestep(pToa, pTimestep, pStartOffset, pDrift)
+%CALCULATETOAATTIMESTEP Calculates the TOA at the given timestep.
+%   Calculates the new TOA at the given timestep.
+%
+%   Parameters:
+%       pToa (double):          The start TOA.
+%       pTimestep (double):     The timestep from start of the soundsource
+%                               in rafos days.
+%       pStartOffset (double):  The start offset of the soundsource.
+%       pDrift (double):        The drift of the soundsource in seconds per day.
+
+%% Calculate new toa
+toa = pToa + pStartOffset + pDrift * pTimestep;
+
+end
+